Is it necessary to take a gradual approach to repentance to avoid boredom and backsliding into sin, and is it permissible to gradually implement acts of worship after repentance?

It is obligatory for a Muslim to immediately repent from all sins, and it is not permissible for him to persist in disobedience. Allah Almighty says: "And turn to Allah in repentance, all of you, O believers, that you might succeed." So, gradual repentance by delaying some of it is a mistake, because death may overtake a servant before he repents from all his sins. Repentance from one sin while leaving another is valid for that sin, but it does not absolve him of the sin of the other one from which he has not repented.

As for gradualism in acts of worship after repentance, if the intention is to perform some obligatory duties and leave others, then it is invalid. All obligatory duties must be performed unless there is an excuse. However, gradualism in performing supererogatory acts and desirable deeds by accustoming oneself to them little by little is a good thing, and it is part of managing and training the soul. The Prophet, peace and blessings be upon him, said: "Indeed, this religion is easy, and no one will ever overpower the religion except it will overpower him. So, aim for what is right, and come as close as you can, and receive good tidings." Therefore, there is no harm in gradualism in supererogatory acts, while obligatory duties and requirements must be performed in full.