Romans 4:20-21 No distrust made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, (21) fully convinced that God was able to do what he had promised.
How lovely. This is the faith (confidence) the justified LIVE by. God can give us a strong faith (thru the word of Christ, by the Spirit) in God, that He can deliver on His promises (which flow from Christ, the Amen!). This is the faith that glorifies God. This is the faith wherein we are sanctified.