‘O son of Adam, so long as you call upon Me, I shall forgive you for what you have done...

Anas ibn Malik (May Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: "Allah, may He be blessed and exalted, said:
‘O son of Adam, so long as you call upon Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you and I would not mind.' "
Reference: Saheeh al Tirmidhi