Question: Ibn Taymiyyah and Salafis say, "It is not necessary to make up the salats that were not performed at their due times. It is sufficient to make repentance." Does one not have to make up missed salats?
ANSWER
[To carry out a salat within its prescribed time period is called adaa. To carry it out after its prescribed time has ended is called qada. Throughout this article, we will use the verb make up to mean to do qada of a salat.]

Yes, Ibn Taymiyyah said, "It is not necessary to make up the salats that one missed deliberately or due to an excuse" (Majmu-ul-Fatawa 12/106).

The opinion of Ibn Taymiyyah is not a proof in our religion. In fact, Islamic courts committed him to prison for his lots of deviant beliefs. Saying "It is not necessary to make up the salats not performed at their due times" means demolishing the religion. Then no one would perform salat, pay zakat, go on hajj, or fast, and people would deem it sufficient to make repentance for them all.

It is written in all fiqh books that it is fard to perform salats at their due times and it is also fard to make them up if they are not performed at their due times. Some excerpts from fiqh books are as follows:

1. It is a major sin to perform a fard salat after its prescribed time without an excuse. This sin is not forgiven when one only makes it up. After making it up, one must make repentance or do hajj as well. When one makes up a fard salat, only the sin of not performing it is forgiven. If one makes repentance without making it up, neither one's sin of abandoning the salat nor one's sin of delaying it is forgiven because giving up the sin is a condition in order for one's repentance to be accepted. (Durr-ul-Mukhtar)

2. One who attaches importance to fard acts of worship but abandons them out of laziness does not become an apostate. In this case, one does not go out of the fold of Islam, but a Muslim who does not do a fard incurs two major sins: 1. One incurs the sin of spending the time allotted for that fard without worship, i.e., delaying it. In order for this sin to be forgiven, one must make repentance. 2. One incurs the sin of not performing the obligatory duty. In order for this major sin to be forgiven, one must make it up immediately. Otherwise, delaying it will add another major sin to the guilt. (Bariqa)

3. If one misses a fard salat with an excuse or without an excuse, it is essential to make it up. (Halabi)

4. It is fard to make up a salat missed forgetfully or deliberately. (Fatawa-i Hindiyya)

5. It is fard to make up immediately fard salats missed with an excuse or without an excuse. (Al-Fiqh 'Ala al-Madhahib al-Arba'ah)

It is stated in hadith-i sharifs:

(If one forgets to perform a salat at its due time, let one perform it whenever one remembers it. There is not any other compensation for a salat that one forgot to perform.) [Tirmidhi, Abu Dawud, Nasai]

(If one misses a salat because of sleeping or forgetting, let one perform it whenever one remembers it.) [Bukhari, Muslim, Tirmidhi, Abu Dawud]

(If one who has forgotten to perform a fard salat remembers it while performing a subsequent salat behind the imam, let one perform that salat behind the imam. After it, let one make up the salat that one forgotten to perform. Then let one repeat the salat that one performed behind the imam.) [Tabarani, Hatib]

(If a person has a missed fard salat, his performing voluntary salat is like [the case of] a pregnant woman who has a miscarriage when she is about to give birth to the baby. The woman cannot be said to be pregnant, nor can she be called a mother anymore. So is this person. Unless he makes up his missed salats, Allahu ta’ala will not accept his voluntary salats.) [Zahira-i Fiqh, Futuh-ul-Ghayb]

The Messenger of Allah slept at the end of the night and could not wake up until sunrise. Then he woke up and made up Salat al-Fajr when the Sun went up. (Nasai)

While it is necessary to make up a salat missed because of forgetting, can it be unnecessary to make up a salat missed intentionally? A salat missed forgetfully is not forgiven. When it is missed deliberately, how can it be forgiven without making it up?