God will erase the sin, but you have to keep the faith and that can be a difficult task for many.
There’s not a believer alive who doesn’t at one time or another question whether they are being faithful (enough). We seek answers from our friends, the church and our ministers and pastors until we return to our comfortable security blanket of man-given answers. On that Jesus said: “Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity. Therefore whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his house upon a rock: And the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock.” Matthew 7:22-24 (KJV)