What is the ruling concerning my prayers between the years 2004 and 2008, and what must I do if they are invalid?

Purity is a prerequisite for the validity of prayer. Whoever experiences a seminal emission must perform ghusl (definition) (ritual bath). If one prays without performing ghusl, their prayer is invalid and must be repeated according to the majority of scholars, because purity is a prerequisite, and if the prerequisite is absent, then the conditioned act is invalid. Some scholars are of the opinion that whoever omits a prerequisite out of ignorance of its obligation is not required to repeat the prayer.

What is given as a fatwa (definition) by us is the obligation to repeat those prayers, because they are a debt upon you, and the debt of Allah is more deserving of being fulfilled. This opinion is more cautious and more absolving of responsibility.

Therefore, you must make up the prayers of those years that you prayed before performing ghusl with the intention of رفع الحدث (removing the ritual impurity), because ghusl without this intention does not remove the impurity according to the majority, due to the saying of the Prophet, peace and blessings be upon him: "Actions are but by intentions." The making up of prayers should be done according to one's capacity, in a way that does not harm the body or livelihood.