Romans 10:14

But how will people call on Him in whom they have not believed? And how will they believe in Him of whom they have not heard? And who will they hear without a preacher (messenger)?

If we don’t believe that God answers prayer, we will not call on Him when we have doubts and disappointments and no faith to believe, because we have not heard enough of the Word. We will not trust what Jesus said to be true; we will not call on the name of the Lord. Our strength and belief in Jesus come from hearing and believing what we hear as true, reliable, and given to us by God.