When does God forgive the repentant person who adheres to righteousness for the first time in their life?

When a servant sins and then repents with sincere repentance, Allah accepts his repentance and rejoices in it. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" (Az-Zumar: 53). The majority of scholars hold that sincere repentance, which fulfills all its conditions, is certainly accepted. The time of acceptance of repentance is from the moment repentance, which fulfills all conditions, is made, as the Prophet, peace and blessings be upon him, said: "Whoever repents before the sun rises from its west, Allah will accept his repentance," and his saying: "The one who repents from sin is like one who has no sin."