On the authority of Abu Hurayrah (may Allah be pleased with him), who said that the Messenger of Allah (ﷺ) said:
When Allah decreed the Creation He pledged Himself by writing in His book which is laid down with Him: My mercy prevails over my wrath. It was related by Muslim (also by al-Bukhari, an-Nasa'i and Ibn Majah)
This hadith reveals that Allah’s mercy will always prevails over His anger. It means that if a faithful believer who commits sins by his nature and then he feels ashamed over them and wants to repent, then he will find that Allah has forgiven all his sins by His unlimited mercy.
Abu Huraira reported Allah's Messenger (ﷺ) as saying:
There are one hundred (parts of) mercy for Allah and He has sent down out of these one part of mercy upon the jinn and human beings and animals and the insects, and it is because of this (one part) that they love one another, show kindness to one another and even the beast treats its young one with affection, and Allah has reserved ninety nine parts of mercy with which He would treat His servants on the Day of Resurrection.
Allah o Akbar! Look, when only by one part of mercy the entire creation loves one another, and then guess the unlimited mercy of Allah Almighty for His creation at the Day of Resurrection? When He will forgive the sinful people’s sins and will make them enter Paradise.