“Jesus replied, “Let the faith of God be in you!”
Mark 11:22, TPT

It’s important that in using your faith, you say what you believe, because if you don’t, it’ll be really something to stick to what you say at the face of any seeming setback.
“For let not that man think that he shall receive any thing of the Lord. A double minded man is unstable in all his ways.” James 1:7-8
Adjusting what you say when the challenge arises, wouldn’t help you. This is why you must spend time with God’s word so you take advantage of God’s grace and say what God desires for you, the Bible tells us in 2 Timothy 2:1 to be strong in that grace, spend time with God’s word and get grace heaped upon grace so instead of leaving to fight another day, because you’ve spent time with God’s word you can expect a miracle and a conclusive victory irrespective, because you serve a God that can prolong the day till you win!
“Then spake Joshua… he said in the sight of Israel, Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ajalon. And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies…” Joshua 10:12-13

Bible Reading Plan: Genesis 47, Luke 3