[ALLAH’S Quran – 4:31] “If you avoid and refrain from committing the major sins which have been forbidden unto you, We will grant you remission for your iniquities and admit you into favor and grant you an honorable entry into the realm of bliss and the beatitude of heaven.”

The Prophet (peace be upon him) has said: {Excerpted from Ibn Kathir Commentary for [4:31]}
“Imam Ahmad recorded that Salman Al-Farisi said, “The Prophet said to me, `Do you know what the day of Al-Jumu`ah is’ I said, `It is the day during which Allah brought together the creation of your father (Adam).’ He said, (I know what the day of Jumu`ah is. Anyone who takes a bath and cleans himself as much as he can and then proceeds for the Friday prayer and remains quiet until the Imam finishes the prayer, all his sins in between the present and the next Friday will be forgiven, as long as major sins were avoided.)”

[Bukhari – Book #51, Hadith #28] “Narrated Abu Huraira: The Prophet said, “Avoid the seven great destructive sins.” The people enquire, “O Allah’s Apostle! What are they? “He said, “To join others in worship along with Allah, to practice sorcery, to kill the life which Allah has forbidden except for a just cause, (according to Islamic law), to eat up Riba (usury), to eat up an orphan’s wealth, to give back to the enemy and fleeing from the battlefield at the time of fighting, and to accuse, chaste women, who never even think of anything touching chastity and are good believers.”

[Bukhari – Book #34, Hadith #267] “Narrated An-Nu’man bin Bashir: The Prophet said “Both legal and illegal things are obvious, and in between, them are (suspicious) doubtful matters. So whoever forsakes those doubtful things lest he may commit a sin, will definitely avoid what is clearly illegal; and whoever indulges in these (suspicious) doubtful things bravely, is likely to commit what is clearly illegal. sins are Allah’s Hima (i.e. private pasture) and whoever pastures (his sheep) near it, is likely to get in it at any moment.”