The believer is pronounced righteous because the Spirit of grace has made him righteous. Justification is a declaration of the fact that Jesus, who stands in man's place, is righteous. Justification is a declaration of what is a fact in the man himself. Justification is so infinite that it cannot be reduced to an intrahuman experience. Justification is an act of grace within man.
Justification is received by faith alone.
Justification comes by faith which has become active by charity. Justification enables God to bring regeneration and sanctification to the heart of the believer. Regenerating grace enables God to justify the believer. Sin still remains in man's nature after justification and regeneration. The believer can claim no merit for good works performed by God's enabling grace.