Isaiah 50:7

For the Lord God helps Me, therefore, I have not been ashamed or humiliated. Therefore, I have made My face like flint, and I know that I shall not be put to shame. 

Faith comes when we are fully convinced that the Word of God is truth. Believing in truth means that we will not waver or doubt the promise. At this point, we set our faces like flint and steadfast as the lies of circumstance parade before us, and the answer of faith arrives. No need to doubt we have the solution!