I have a question to ask and i don't really know where and whom to ask about it. So, I’ve been neglecting salah for 24 years of my life, I’ve started to pray fully 5x times a day and I’ve been wondering how do i replace all the salah that I’ve been neglecting before. How do i know the numbers to replace, and what should i do? From what i heard, even if you seek for His forgiveness, you still have to pay back all the salah that you’ve missed out. Same goes to fasting.
Short answer: No, you do not need to make up those missed prayers.
The opinion of the founders of the four schools (Malik, al-Shafi`i, Ahmad and Abu Hanifah) is that a Muslim should make up any prayers missed after puberty even if this amounts to decades worth of missed prayers. Their reasoning is that since the prayer is obligatory on every Muslim, a missed prayer is like debt that one has to pay back.
Comparing a missed prayer to debt is known as qiyas (‘analogy’). The Islamic texts do not give us any clear pointers toward whether a person who habitually abandons the prayer should make them all up or not, this is an issue that is never mentioned in the Quran or hadith.
Ibn Taymiyyah rejects the debt analogy and provides a better analogy, that of intentionally missing the Friday prayer. People who intentionally delay the Friday prayer by not performing it in its proper time are not allowed to hold the Friday prayer later on to make up for it. The Friday prayer has a set time and it is only valid during that time.
As for making up missed prayers, according to Ibn Taymiyyah this only applies to cases when one’s daily life is interrupted by something that prevents them from praying in its proper time. Those who intentionally abandon the prayer cannot make it up; they have sinned, and once they repent, they should simply resume a Muslim’s life.
If you miss the Friday prayer intentionally by praying at home, there is no way to make it up, you cannot go to extra Friday prayers since there is no such thing as extra Friday prayers. I think this might be Ibn Taymiyyah’s point regarding the Friday prayer analogy. It appears that in Ibn Taymiyyah’s view the prayer is like a train that you either catch or miss. If you miss it by performing it defectively (such as by praying the Friday prayer at home) or by simply abandoning it, then you miss the train and there is no way to get back on it, since the prayer for each time period belongs to that time period and cannot be prayed outside of it. The noon prayer for March 5, 2018 belongs to a set period in time (say 12:30 PM to 4:00 PM), if one intentionally misses the prayer belonging to this period of history, then there is no way for them to make it up (unless they get on a time machine).
Ibn Taymiyyah’s view seems more like common sense and is, of course, far more humane, therefore I prefer it.
Ibn Taymiyyah’s view regarding missed fasts is similar; if the fast is intentionally abandoned, one is not required to make it up.