If we have been granted faith in Christ alone, our sins have been forgiven. This is past tense. The sick man could do nothing to heal himself, he knew it, had faith in the LORD, and was informed of the present reality of his sins being forgiven. This is a excellent picture of the gospel of grace.
If we think our sins require further repentence for justification, is that faith truly in Christ alone? Is this trusting in the cross of Christ satisfying the laws just requirement on it's own or are we trusting in our merit to finish the job? Only one is the truth. May God give light.
Sovereigngrace
Matthew 9:2 KJVS
And, behold, they brought to him a man sick of the palsy, lying on a bed: and Jesus seeing their faith said unto the sick of the palsy; Son, be of good cheer; thy sins be forgiven thee.