We believe that Allah Almighty revealed the books and sent the messengers, so that people may have no excuse before Him. Allah, the Exalted, says: {These messengers were sent as bearers of glad tidings and as warners, so that the people may have no excuse before Allah after [the coming of] the messengers. For Allah is All-Mighty, All-Wise.} [Surat an-Nisā’: 165] Allah Almighty informs that the polytheists cited the predestination as an excuse for them to fall into polytheism, and He reveals the falsity of their statement and made them taste His punishment. He, Glorified be He, says: {Those who associate partners with Allah will say: "If Allah had willed, neither we nor our forefathers would have associated anything with Him, nor would we have made anything forbidden." Likewise, those who came before them rejected the truth until they tasted Our punishment. Say: "Do you have any knowledge that you can present to us? You follow nothing but assumption and you do nothing but lie."} [Surat al-An‘ām: 148] If the predestination was an excuse for them to fall into polytheism, Allah Almighty would not have made them taste His punishment.
‘Ali (may Allah be pleased with him) reported: We were sitting with the Prophet (may Allah's peace and blessings be upon him) and he had a stick with which he was scraping the earth. He said: "There is no one among you except that his place in Hellfire or Paradise was predestined." A man said: "Should we rely on that, O Messenger of Allah?" He said: "No, do good deeds, for everyone will find it easy to do such deeds (it will lead him to his destined place)." Then, he recited: {As for the one who gives in charity and fears Allah.} [Surat al-Layl: 5] [Narrated by Al-Bukhāri (6605), Muslim (2647), At-Tirmidhi (2136), and Ibn Mājah (78)] So, the Prophet (may Allah's peace and blessings be upon him) instructed us to do good deeds and forbade us from solely relying upon the predestination.
We believe that a person may cite the predestination as an excuse for committing sins after repenting from them. Humayd ibn ‘Abdur-Rahmān related that Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Adam and Mūsa debated. Mūsa said to Adam: 'You are Adam whose sin drove you out of Paradise.' Adam said to him: 'You are Mūsa, whom Allah chose for His messages and speech, and you blame me for something which Allah had decreed for me before I was created?' Thus, Adam won the argument with Mūsa; thus Adam won the argument with Mūsa." [Narrated by Al-Bukhāri (6614), Muslim (2652), Abu Dāwūd (4701), At-Tirmidhi (2134), and Ibn Mājah (80)]
Mutarrif ibn ‘Abdullāh ibn ash-Shikhkhīr (may Allah have mercy upon him) said: "We are not left to the predestination in the Qur’an, yet He informed us in the Qur’an that we will end up to it." [As-Sunnah for ‘Abdullāh ibn Ahmad (2/412)] Muhammad ibn Sīrīn (may Allah have mercy upon him) said: "If the deniers of the predestination are not among those who ridicule the verses of Allah Almighty, I do not know then who they can be!" [As-Sunnah for ‘Abdullāh ibn Ahmad (2/432) and Sharh Usūl I‘tiqād Ahl As-Sunnah Wa Al-Jamā‘ah (4/696)]
Ibn Wahb and some others said: Mālik was asked about the deniers of the predestination as to whether we should stop talking to them, and he replied: "Yes, if they are aware of their error." He said: "And you should command them to do what is right and forbid them from doing what is wrong, and tell them about their difference. You should not speak to them in a humble manner, nor should you pray upon their dead or attend their funerals. And, in my view, you should not marry from them." In another version, he added: "Allah says: {A believing slave is better than a free polytheist} [Surat al-Baqarah: 221]." In another version by Ash'hab, he said: 'You should not pray behind them, and if you find them in a garrison, drive them out of it." [Tartīb Al-Madārik Wa Taqrīb Al-Masālik (1/91)]
We believe that it is permissible for a person to cite the predestination as an argument as far as afflictions are concerned. Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "A strong believer is better and dearer to Allah than a weak believer, and there is good in both. Adhere to whatever brings you benefit, seek the help of Allah and do not feel helpless. If something befalls you, do not say: ‘Had I done such-and-such, it would have been such-and-such.’ Indeed, 'if' opens the way before the devil to act." [Narrated by Muslim (2664) and Ibn Mājah (79)]
Commenting on the verse: {Those when afflicted with a disaster, they say, "We belong to Allah, and to Him we will return"} [Surat al-Baqarah: 156], Ibn ‘Abbās (may Allah be pleased with him) said: Allah informs that if the believer leaves the affair to Allah, turns to Him, and says "We belong to Allah, and to Him we will return" upon the occurrence of a disaster, he will gain three good things: blessings from Allah upon him, and mercy, and following the path of guidance. And the Prophet (may Allah's peace and blessings be upon him) said: "Whoever says: 'We belong to Allah, and to Him we will return' upon the occurrence of a disaster, Allah will compensate him for his disaster, give him a good outcome, and grant him a good alternative with which he will be pleased." [Narrated by At-Tabari in At-Tafsīr (2/707) - (3/223), Ibn Abi Hātim in At-Tafsīr (1421), At-Tabarāni in Al-Kabīr (13027), and Al-Bayhaqi in Ash-Shu‘ab (9240)]