Entering Islam will save a person in this world and the hereafter, for Islam is the religion which affirms the oneness of Allah (may He be glorified) and does not associate anything with Him. It is the message that was brought by all the Messengers and Prophets. In this hadith, the Prophet (blessings and peace of Allah be upon him) states that if a disbeliever enters Islam and becomes a good Muslim, and becomes a Muslim in the true sense of the word, with no trace of doubt, believing outwardly and inwardly, then Allah will absolve the bad deeds that he committed, meaning the sins, both minor and major, that he committed before he became Muslim, by His grace. Then after becoming Muslim he will be treated fairly and equitably, meaning that Allah will requite him appropriately for everything that he does, whether it is good or bad. So he will be requited for good deeds with reward, and for bad deeds with punishment. He will be rewarded tenfold for every good deed, and that reward may be multiplied up to seven hundredfold. As for bad deeds, each bad deed will be recorded as just one deed, and he will be requited accordingly. Or Allah may pardon him, by His grace, kindness and mercy, so He will not punish him for doing it. This hadith indicates that Islam erases whatever sins came before it. .