Search me, God, and know my heart,
test me, and know my anxious thoughts!
See if I there is any offensive way in me,
and lead me in the way everlasting!
Psalm 139, 23f.

The first and last verses of this Psalm are about God exploring us, knowing our heart and our mind: “You have searched me, Lord, and You know me. You know when I sit and when I rise. You perceive my thoughts from afar.  You discern my going out and my lying down;  Whether I walk or rest, it is known to you; you are familiar with all my ways.” – so begins the Psalm. And the answer is the verses above.
At first it seems to be a general knowledge, but in the course of the Psalm it becomes a personal thing: Know me! Guide me! I do not want to go astray, I want to go your way!
We often get the feeling that God controls us and judges us as if He were looking for our faults. But we soon realize that God’s thoughts about us are marked by love, that He prefers to forgive and forget rather than to judge and damn us. His presence is grace, love, acceptance, confidentiality and warmth. That is why David comes to the conclusion in this prayer: I entrust myself to Him. Because I don’t always understand myself and don’t always know my own motives so well, I want to entrust myself to Him, so that He will search me and purify me, so that He will turn me away from wrong paths and I will walk on the path that pleases Him, on the eternal way, on the narrow way that leads to heaven.
It is good when He can search us. When He searches the chambers of our bodies, He finds disease-causing changes and can heal them before an illness breaks out. When He searches our thoughts, He can straighten many a thought that would otherwise remain crooked. If He can explore our feelings, many an ego will be exposed, self-pity recognized, bitterness and unforgiveness discovered, sin uncovered. Then He can forgive and heal, liberate and revive.

Yes, Lord, I entrust myself to You. Explore my body and heal what is in disorder. Purify my thoughts! Sanctify my feelings so that they correspond to You! Lord, I want to do You honour, for You love me so boundlessly.