Om Swami
What does it mean to surrender to God?
Surrender is firm faith that God will save you
In the Vaishnava scriptures, sharanagati (surrender) means one who has already gone into God's refuge, and its foremost sign is a firm faith that God is yours and will save you. You can surrender only to someone you hold higher than yourself.
The firm faith that I have an Ishwar and that He alone will save me is the foremost sign of sharanagati (surrender).