Surrendering one's heart to God is not a passive process, but rather an extremely active one.
It is not giving up.
It is not merely "letting go."
It does not mean allowing people and situations to push you wherever they will and assuming that you have to accept all of it unflinchingly because it must be part of God's plan.
Surrendering to God's will and leading and purpose is an inherently active process. Why? Because it must be a conscious and courageous choice--a declaration that you have the ability to walk in any number of directions, but you will choose to walk with God. No matter where He leads.