From the route of Anas, may Allah accepts his deeds, who said: I have heard the Messenger of Allah, sallallahu ^alayhi wa sallam, say (in a Hadith Qudsiyy):
<< Allah , the Exalted, said:
‘O son of Adam, so long as you make supplication to Me and plead with Me with hopefulness, I shall forgive you regardless of your sins. O son of Adam if your sins reach the sky and then you ask for My forgiveness, I shall forgive you.
O son of Adam if you come on the Day of Judgment with sins that almost fill the earth but as a believer, clear of associating partners with Me, I shall reciprocate with forgiveness that almost fill the earth.’ >>
This Hadith was narrated by at-Tirmidhiyy who said: This Hadith is Hasan Sahih.