[The ruling on making up the prayer for one who abandoned it deliberately]

Answer—and Allah grants success: Whoever is in that state is, more likely than not, included under the ruling of the unbeliever and the apostate. Accordingly, he is not required to make up what has passed of prayer, fasting, and zakāt.
Proof for this: Allah Most High says regarding the polytheists: “But if they repent, establish prayer, and give zakah, then they are your brothers in religion …” [At-Tawbah:11] Allah, the Exalted, has made in this verse the establishment of prayer and the giving of zakah a condition for the polytheists to enter into the jurisdiction of Islam.
And in the well-known ḥadīth of the Prophet —May Allah bless him and his family and grant them peace—: “Islam is built on five: bearing witness that there is no god but Allah and that Muḥammad is the Messenger of Allah, establishing the prayer, giving the zakāt, fasting Ramadan, and pilgrimage to the House for whoever is able to find a way to it,” or as he said.
There are analogous texts that support what we have stated; among them His saying in the verse about usury: “So whoever has received an admonition from his Lord and desists may have what is past …” [Al-Baqarah:275].
He did not obligate, in this verse, those who consumed usury to return what they had consumed.
And among them His saying in the verse regarding the highway robber:
“Except for those who repent before you apprehend them—then know that Allah is Forgiving, Merciful.” [Al-Mā’idah:34].
Imām al-Hādī—peace be upon him—and others used this verse as evidence that if the highway robber repents, everything he committed during his brigandage—blood, wealth, and other matters—falls from him.
What Allah Most High mentioned in these two verses about those who consumed usury and about the highway robbers is from His facilitation of the path of repentance and encouragement toward it—something evident to all. He, exalted is He, says:
“Allah intends for you ease and does not intend for you hardship.” [Al-Baqarah:185].
And in the ḥadīth: “Make things easy and do not make them difficult.”
Yes, all of this supports what we advanced. And in another ḥadīth of the Prophet —May Allah bless him and his family and grant them peace—: “Islam wipes out what came before it, and repentance wipes out what came before it.”
Reason likewise supports what we mentioned: the intellect perceives the benefit in this ruling, for imposing make-up of long-neglected duties repels people from repentance—especially if the neglect spans decades—or if it would require stripping all one’s wealth to pay back past zakāt.
Further support comes from what is established in uṣūl al-fiqh: making up (qaḍāʾ) is not entailed by the original command; rather, it requires a new command. They have adduced evidences for this that are set out in the books of legal theory.
In this matter we only find a command to the forgetful and the sleeping person to pray, not to the one who deliberately left it.
As for fasting, there is a command to make it up for the sick, the traveler, and the pregnant and nursing, but there is no text obligating make-up for the deliberate breaker; and “your Lord is never forgetful.” [Maryam:64].
It may be that Allah Most High only mentioned the forgetful, the sleeping, the sick, the traveler, the pregnant and nursing women, the menstruant, and those with excuses because it is not conceived of nor expected from a Muslim that he leave an obligation except out of excuse or error/forgetfulness; as for leaving it deliberately in defiance of Allah, that is not among their attributes—it is among the attributes of the unbelievers and the openly disobedient. Allah says: “And woe to the polytheists—those who do not give the zakah, and in the Hereafter they are disbelievers.” [Fuṣṣilat:6–7].
And He says about the people of the Fire:
“‘What landed you in Saqar?’ They will say: ‘We were not of those who prayed, nor did we feed the poor; we used to indulge with those who indulge, and we used to deny the Day of Recompense.’” [Al-Muddaththir:42–46].
From here, Allah mentioned the rulings of the believers, obligating them—when they miss something—to make it up, then He mentioned the rulings of the unbelievers and the openly disobedient, calling them to repentance and urging them toward it: “Say to those who disbelieve that if they cease, what has previously occurred will be forgiven for them …” [Al-Anfāl:38].
And in the ḥadīth: “Repentance wipes out what came before it.”
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1