Psalm 104:16

Without sap, the tree cannot flourish or even exist. Vitality is essential to a Christian. There must be life—a vital principle infused into us by God the Holy Spirit, or we cannot be trees of the Lord. The mere name of being a Christian is only a dead thing; we must be filled with the spirit of divine life.

This life is mysterious. We do not understand the circulation of the sap—by what force it rises, and by what power it descends again. So the life within us is a sacred mystery. Regeneration is accomplished by the Holy Spirit entering into a person and becoming that person’s life. This divine life in a believer afterward feeds upon the flesh and blood of Christ and is thus sustained by divine food, but from where it comes and to where it goes, who can explain to us?

What a secret thing the sap is! The roots go searching through the soil with their tiny rootlets, but we cannot see them absorb the various gases or transform minerals into plant matter; this work is done in the dark. Our root is Christ Jesus, and our life is hidden in Him; this is the secret of the Lord.

The root of the Christian life is as secret as the life itself. How permanently active is the sap in the cedar! In the Christian, the divine life is always full of energy—not always in fruit-bearing, but in inward operations. The believer’s graces are not all of them in constant motion, but his life never ceases to palpitate within.

He is not always working for God, but his heart is always living on Him. As the sap manifests itself in producing the foliage and fruit of the tree, so with a truly healthy Christian, his grace is externally manifested in his daily conduct and interactions. If you talk with him, he cannot help speaking about Jesus. If you notice his actions, you will see that he has been with Jesus. He has so much sap within that it must fill his conduct and interactions with life.