2 Corinthians 3:4-6
Such confidence we have through Christ toward God.

• Romans 4:20-24
  …yet, with respect to the promise of God, he did not waver in unbelief but grew strong in faith, giving glory to God, and being fully assured that what God had promised, He was able also to perform. Therefore IT WAS ALSO CREDITED TO HIM AS RIGHTEOUSNESS. Now not for his sake only was it written that it was credited to him, but for our sake also, to whom it will be credited, as those who believe in Him who raised Jesus our Lord from the dead…
• 2 Timothy 1:12
  For this reason I also suffer these things, but I am not ashamed; for I know whom I have believed and I am convinced that He is able to guard what I have entrusted to Him until that day.

Not that we are adequate in ourselves to consider anything as coming from ourselves, but our adequacy is from God, who also made us adequate as servants of a new covenant, not of the letter but of the Spirit; for the letter kills, but the Spirit gives life.