Forgiveness for All Previous Sins
When someone converts to Islam, God forgives all of his previous sins and evil deeds. A man called Amr came to the Prophet Muhammad
After converting to Islam, the person will be rewarded for his or her good and bad deeds according to the following saying of the Prophet Muhammad
And if he does do it, (a reward of) ten to seven hundred or many more times (the reward of the good deed), will be recorded for him. And if someone intends to do a bad deed but does not do it, a good deed will be recorded for him. And if he does do it, a bad deed will be recorded against him or God will wipe it out.}2
(1) Narrated in Saheeh Muslim, #121, and Mosnad Ahmad, #17357.
(2) Narrated in Mosnad Ahmad, #2515, and Saheeh Muslim, #131.