God Commands to Believe – therefore – Man's Own Faith is a Deed of the Law

Romans 3:28 Therefore we conclude that a man is justified by faith without the deeds of the law.

Jesus is the essence of faith. He is "the faith" once delivered unto the saints. Therefore, we conclude that a man is justified by Jesus (Galatians 2:16) without the deeds (or works) of the law. One of the works of the law is that of faith.

1 Thessalonians 1:3 Remembering without ceasing your work of faith, ...

Man's deed, or work of faith, cannot justify him. He can only be justified by Jesus' work of faith performed on the elect sinner's behalf from the foundation of the world.