How can the soul be completely convinced that God forgives its sins?

St. Basil the Great answers, “She notices within herself this tendency that says: ‘I hate and abhor lying’ (Ps. 119:163). When God sent His only Son for the forgiveness of our sins, He forgave us as long as we believe in His role. David the Psalmist sings of mercy and justice (Ps. 101:1), testifying that God is merciful and just (Ps. 115:5), so it is very important for the words of the Apostles and Prophets that pertain to repentance to be entwined within us, and also their words about God’s righteous judgments and His perfect mercy in the forgiveness of sins.”¹⁴⁵²