Justification by Faith Alone

Isa. 54:17 No weapon that is formed against thee shall prosper; and every tongue that shall rise against thee in judgment thou shalt condemn. This is the heritage of the servants of the LORD, and their righteousness is of me, saith the LORD.

Romans 8:30 Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified. 31What shall we then say to these things? If God be for us, who can be against us? 32He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things? 33Who shall lay any thing to the charge of God's elect? It is God that justifieth. 34Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.

Paul's theology of justification by faith alone apart from the works of the law really is depended upon the OT prophets, he did not invent this doctrine, but because of his Pharisee school training he was able to dig out these verses from the prophets. This teaching of justification by faith alone is not clearly taught by any other apostles, and we thank God for Paul's letters.