Hebrews 3:12

Take care, brothers and sisters, that there not be in any one of you a wicked, unbelieving heart (which refuses to trust and rely on the Lord, a heart) that turns away from the living God.

Trust is essential to God for our prayers to be answered. Suppose we only know some Gods’ promises to be able to trust in Him. Then we need to study the Word until we do. We have a part to play, and keeping a believing heart for the promises of God is our responsibility. We can transform our hearts with time in the Word and remove all doubt and believe.