What is the soul and why is that question important? It's important because the soul is what God is calling you to surrender.
God calls us to love Him with all our heart, soul, mind, and strength (Luke 10:27).
In order for us to surrender our soul to God, we must first know what the soul is.
The soul is composed of three main parts:
Your mind, or your innermost thoughts.
Your will, or the desires of your heart.
Your emotions, or your feelings and personality.
God also calls for your whole spirit, soul, and body to be preserved blameless at the coming of our Lord Jesus Christ (1 Thessalonians 5:23).
But there's a problem. The flesh wages war against the soul (1 Peter 2:11). This is why we must crucify our flesh, or our worldly desires. Let go of what you want in this life and allow God to give you a new heart with new desires.
When you can surrender your soul, or who you are as a person, that's when the Spirit of God can truly operate in you for His glory.
Let it not be your will, but let God's will be done in you.