God says: “And if the followers of the Book had believed and guarded (against evil), We would certainly have covered their evil deeds and We would certainly have made them enter gardens of bliss.” [1]
On the same topic, God says: “O you who believe! If you are careful of (your duty to) Allah, He will grant you a distinction and do away with your evils and forgive you; and Allah is the Lord of infinite grace.” [2]
About those who, with the temptations of Satan, drank wine but returned and exercised piety, God says:“On those who believe and do good there is no blame for what they ate, when they are careful (of their duty) and believe and believe, then they are careful (of their duty) and believe, then they are careful (of their duty) and do good (to others), and Allah loves who do good (to others).” [3] God has used the word Taqwa three times in this verse which shows its significance. Furthermore, God does not desire a temporary piety but a permanent and continued one, a piety accompanied with faith, good deeds and benevolence. Such a piety removes evil acts and sins.
9) Piety, A Heavenly Blessing
About piety and heavenly blessings, God has said: “And if the people of the towns had believed and guarded (against evil), We would certainly have opened up for them blessings from the heaven and the earth, but they rejected, so We overtook them for what they had earned.” [4]
[1] Qur'an, 5:65.
[2] Qur'an, 8:29.
[3] Qur'an, 5:93.
[4] Qur'an, 7:96.
source : http://www.maaref-foundation.com