Phototropism and Heliotropism

Botany can tell us much about how a plant thrives when it grows toward the light, and plant physiology can help us understand the mechanism of how a plant indeed orients its growth toward the light. The process of directed growth with respect to light is called phototropism. In some cases, though, the light is dynamic and moves. In that case the plant must track, for example, the sun as it moves from the east horizon in the morning, overhead, and to the west horizon by evening. This process is called heliotropism and operates in a similar fashion to phototropism. Obviously, however, heliotropism is far more dynamic and involves constant checking and realignment with the moving source of light. The benefit of this constant reorientation is improved photosynthesis and resulting vigor of the plant. The religious value of this botanical concept is transparent and obviously was used in scripture.

First we need a light source, so the Bible provides this starting point. Notice how it is God's first act of creation!

Genesis 1

1 In the beginning when God created the heavens and the earth,

2 the earth was a formless void and darkness covered the face of the deep, while a wind from God swept over the face of the waters.

3 Then God said, "Let there be light"; and there was light.

4 And God saw that the light was good; and God separated the light from the darkness.

5 God called the light Day, and the darkness he called Night. And there was evening and there was morning, the first day.

6 And God said, "Let there be a dome in the midst of the waters, and let it separate the waters from the waters."

7 So God made the dome and separated the waters that were under the dome from the waters that were above the dome. And it was so.

8 God called the dome Sky. And there was evening and there was morning, the second day.

9 And God said, "Let the waters under the sky be gathered together into one place, and let the dry land appear." And it was so.

10 God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good.

11 Then God said, "Let the earth put forth vegetation: plants yielding seed, and fruit trees of every kind on earth that bear fruit with the seed in it." And it was so.

12 The earth brought forth vegetation: plants yielding seed of every kind, and trees of every kind bearing fruit with the seed in it. And God saw that it was good.

13 And there was evening and there was morning, the third day.

14 And God said, "Let there be lights in the dome of the sky to separate the day from the night; and let them be for signs and for seasons and for days and years,

15 and let them be lights in the dome of the sky to give light upon the earth." And it was so.

16 God made the two great lights - the greater light to rule the day and the lesser light to rule the night - and the stars.

17 God set them in the dome of the sky to give light upon the earth,

18 to rule over the day and over the night, and to separate the light from the darkness. And God saw that it was good.

I have preached before on the importance of the light coming before the sun. Anyway, now we have our light and our plants and the botanical story is a matter of evolution of a simple mechanism for heliotropism. But the analogy needs to be expanded into the human picture from the world of botany. And indeed the scriptures oblige...with an almost parallel passage...first we need the light, and then the sun...in this case the S-O-N! This is the source of the light for humankind.

John 1

1 In the beginning was the Word, and the Word was with God, and the Word was God.

2 He was in the beginning with God.

3 All things came into being through him, and without him not one thing came into being. What has come into being

4 in him was life, and the life was the light of all people.

5 The light shines in the darkness, and the darkness did not overcome it.

This light for human growth in life was Jesus, a point obviously made clear in a later passage.

John 3

16 "For God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life.

17 Indeed, God did not send the Son into the world to condemn the world, but in order that the world might be saved through him.

18 Those who believe in him are not condemned; but those who do not believe are condemned already, because they have not believed in the name of the only Son of God.

19 And this is the judgment, that the light has come into the world, and people loved darkness rather than light because their deeds were evil.

20 For all who do evil hate the light and do not come to the light, so that their deeds may not be exposed.

21 But those who do what is true come to the light, so that it may be clearly seen that their deeds have been done in God."

Our spirit is lost to God unless we "come to the light" and follow it. We must become like the plants and "track" Him. Will you take up the challenge? Will you follow Jesus? This was the choice for each of the original disciples.

Matthew 9

9 As Jesus was walking along, he saw a man called Matthew sitting at the tax booth; and he said to him, "Follow me." And he got up and followed him.

Mark 8

34 He called the crowd with his disciples, and said to them, "If any want to become my followers, let them deny themselves and take up their cross and follow me."

John 8

12 Again Jesus spoke to them, saying, "I am the light of the world. Whoever follows me will never walk in darkness but will have the light of life."

John 9

1 As he walked along, he saw a man blind from birth.

2 His disciples asked him, "Rabbi, who sinned, this man or his parents, that he was born blind?"

3 Jesus answered, "Neither this man nor his parents sinned; he was born blind so that God's works might be revealed in him.

4 We must work the works of him who sent me while it is day; night is coming when no one can work.

5 As long as I am in the world, I am the light of the world.

6 When he had said this, he spat on the ground and made mud with the saliva and spread the mud on the man's eyes,

7 saying to him, "Go, wash in the pool of Siloam" (which means Sent). Then he went and washed and came back able to see.

John 12

26 Whoever serves me must follow me, and where I am, there will my servant be also. Whoever serves me, the Father will honor."

John 12

34 The crowd answered him, "We have heard from the law that the Messiah remains forever. How can you say that the Son of Man must be lifted up? Who is this Son of Man?"

35 Jesus said to them, "The light is with you for a little longer. Walk while you have the light, so that the darkness may not overtake you. If you walk in the darkness, you do not know where you are going.

36 While you have the light, believe in the light, so that you may become children of light." After Jesus had said this, he departed and hid from them.

Jesus himself made the call to us to follow Him. God is not a static light but is instead dynamic. Jesus clearly did not say to simply point yourself at Him. No, clearly we must turn away from our own ways and actively track Him...follow Him.

1John 2

3 Now by this we may be sure that we know him, if we obey his commandments.

4 Whoever says, "I have come to know him," but does not obey his commandments, is a liar, and in such a person the truth does not exist;

5 but whoever obeys his word, truly in this person the love of God has reached perfection. By this we may be sure that we are in him:

6 whoever says, "I abide in him," ought to walk just as he walked.

7 Beloved, I am writing you no new commandment, but an old commandment that you have had from the beginning; the old commandment is the word that you have heard.

8 Yet I am writing you a new commandment that is true in him and in you, because the darkness is passing away and the true light is already shining.

9 Whoever says, "I am in the light," while hating a brother or sister, is still in the darkness.

10 Whoever loves a brother or sister lives in the light, and in such a person there is no cause for stumbling.

11 But whoever hates another believer is in the darkness, walks in the darkness, and does not know the way to go, because the darkness has brought on blindness.

12 I am writing to you, little children, because your sins are forgiven on account of his name.

13 I am writing to you, fathers, because you know him who is from the beginning. I am writing to you, young people, because you have conquered the evil one.

14 I write to you, children, because you know the Father. I write to you, fathers, because you know him who is from the beginning. I write to you, young people, because you are strong and the word of God abides in you, and you have overcome the evil one.

15 Do not love the world or the things in the world. The love of the Father is not in those who love the world;

16 for all that is in the world -- the desire of the flesh, the desire of the eyes, the pride in riches -- comes not from the Father but from the world.

17 And the world and its desire are passing away, but those who do the will of God live forever.

The path of our lives is not straight nor simple and we are given free will to chose our direction. The important choice is not to be swayed by the temptations of darkness but to keep our eyes and minds focused upon the light. If we follow the light of Jesus, then our pathway is clear and our success is assured. An example of such a choice is mentioned in...

James 1

17 Every generous act of giving, with every perfect gift, is from above, coming down from the Father of lights, with whom there is no variation or shadow due to change.

James is saying that when we love and give we follow God's plan and when we do there is no variation of light or presence of shadow which might drive us to change our orientation like a plant that is out of alignment with the light. In other words being generous with one another puts us in correct alignment with God's light. This is what we must do!

A passage in Revelation tells us the benefit of correct alignment...

Revelation 14

4 It is these who have not defiled themselves with women, for they are virgins; these follow the Lamb wherever he goes. They have been redeemed from humankind as first fruits for God and the Lamb.

Revelation is hard symbolic reading. To me, this passage says that the first fruits for salvation are those whose purity and fidelity...virgins if you will...in following Jesus is perfect. In other words, the closer you stick to Jesus' plan, the better you are at following Him, the more likely you are to reach His kingdom!

In the conversion of Saul, the anti-Christians, into the apostle Paul, God chose the analogy of light and bringing Gentiles (that's us!) into that light. He was calling Paul to be a witness to the light, and to become a lens to focus that light upon the Gentiles. In fact, if you remember, Saul was blinded by the light until his conversion was complete.

Acts 26

15 I asked, 'Who are you, Lord?' The Lord answered, 'I am Jesus whom you are persecuting.

16 But get up and stand on your feet; for I have appeared to you for this purpose, to appoint you to serve and testify to the things in which you have seen me and to those in which I will appear to you.

17 I will rescue you from your people and from the Gentiles -- to whom I am sending you

18 to open their eyes so that they may turn from darkness to light and from the power of Satan to God, so that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.'

After Saul was blinded by God's light, his recovery of sight was accomplished by his gradual repentence and conversion into the apostle and evangelist, Paul! As the transformed man and with his life clearly focused on Jesus, he indeed did serve as a lens for God's light. He witnessed to the Gentiles and focuses our attention today on the practical orientation of our lives toward the light of Jesus.

Rom. 13

11 Besides this, you know what time it is, how it is now the moment for you to wake from sleep. For salvation is nearer to us now than when we became believers;

12 the night is far gone, the day is near. Let us then lay aside the works of darkness and put on the armor of light;

13 let us live honorably as in the day, not in reveling and drunkenness, not in debauchery and licentiousness, not in quarreling and jealousy.

14 Instead, put on the Lord Jesus Christ, and make no provision for the flesh, to gratify its desires.

From a botanical point of view, heliotropism in sunflowers involves the amount of light on each of two opposite leaves. The leaf that is in the shade produces more auxin and exports that auxin down the shaded side of the stem. This causes the stem to grow faster on the shaded side and the stem to curve toward the light until the relative amount of sun on the two leaves is equal. When this is accomplished, both leaves are putting out the same amount of auxin and stem grows straight toward the light source.

I think Paul is saying that we need to think about the "dark" sides of our own lives and work on making that part of our personality grow faster so that our whole personality is growing toward the light of God. We need to find the balance between the two sides of our personality...the evil and the good...and work toward making it 100% good. Paul continues in his letter to the...

Ephesians 5

8 For once you were darkness, but now in the Lord you are light. Live as children of light--

9 for the fruit of the light is found in all that is good and right and true.

10 Try to find out what is pleasing to the Lord.

11 Take no part in the unfruitful works of darkness, but instead expose them.

12 For it is shameful even to mention what such people do secretly;

13 but everything exposed by the light becomes visible,

14 for everything that becomes visible is light. Therefore it says, "Sleeper, awake! Rise from the dead, and Christ will shine on you."

John picks up the thread...

1John 1

5 This is the message we have heard from him and proclaim to you, that God is light and in him there is no darkness at all.

6 If we say that we have fellowship with him while we are walking in darkness, we lie and do not do what is true;

7 but if we walk in the light as he himself is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin.

And Peter added in the same paradigm...

1Peter 2

9 But you are a chosen race, a royal priesthood, a holy nation, God's own people, in order that you may proclaim the mighty acts of him who called you out of darkness into his marvelous light.

So the apostles learned this lesson about following the light of God and staying away from the ways of sin and death. I'd like to finish this message with two passages again from Paul. He was the apostle who had to make the hardest turn from darkness and into light his eyes were unaccustomed to...that blinded him. Above all this man clearly knew what it means to deny your old self, to turn away from darkness, and grow and flourish in the Light of Christ. He wrote...

Romans 8

3 For God has done what the law, weakened by the flesh, could not do: by sending his own Son in the likeness of sinful flesh, and to deal with sin, he condemned sin in the flesh,

4 so that the just requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit.

5 For those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit set their minds on the things of the Spirit.

6 To set the mind on the flesh is death, but to set the mind on the Spirit is life and peace.


9 But you are not in the flesh; you are in the Spirit, since the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.

10 But if Christ is in you, though the body is dead because of sin, the Spirit is life because of righteousness.

11 If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ from the dead will give life to your mortal bodies also through his Spirit that dwells in you.


37 No, in all these things we are more than conquerors through him who loved us.

38 For I am convinced that neither death, nor life, nor angels, nor rulers, nor things present, nor things to come, nor powers,

39 nor height, nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.


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