In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Imaam As-Sadi [may Allaah have mercy upon him] said:

Likewise, is that which many enemies of Islam and hypocrites have fabricated that belief in Qadaa Wal Qadar brings about apathy and submission without action. This claim of theirs is a clear slander and an outright lie, for indeed the religion of Islaam commanded with two mighty fundamentals and all affairs cannot be accomplished except by gathering them together. The first affair is belief in Allāh’s Qadaa Wal Qadar, and that all affairs and their means are tied to Qadaa Wal Qadar, and that what Allāh wills occurs and what He does not will cannot occur. The second principle is the command to perform beneficial deeds in the religion and worldly matters, and to distance from the causes of harm. Each of these fundamentals supports the other, because belief in Qadaa Wal Qadr aids the performers of righteous deeds, makes them active and enjoins on them to seek a breakthrough in difficult matters, whilst relying on Allāh and seeking help from His Might and Power; removes fear of the creation from their hearts, who neither own the power to benefit nor cause harm. This is an affair related to the Allaah’s Qadaa Wal Qadar, for indeed Allaah informed us that He makes things come into existence through their means and causes. And due to this, Allāh has mentioned these two fundamentals together in many places in His Book, such as His statement: [لمن شاء منكم أن يستقيم وما تشاءون إلا أن يشاء الله رب العالمين – To whomsoever among you who wills to walk straight, and you will not, unless (it be) that Allah wills, the Lord of the ‘Alamin (mankind, jinns and all that exists)]. [Surah At-Takweer. Aayaat 28-29]

And Allaah’s statement:

ڪَلَّآ إِنَّهُ ۥ تَذۡكِرَةٌ۬
فَمَن شَآءَ ذَڪَرَهُ
وَمَا يَذۡكُرُونَ إِلَّآ أَن يَشَآءَ ٱللَّهُ‌ۚ

Nay, verily, this (Qur’an) is an admonition, So whosoever will (let him read it), and receive admonition (from it)! And they will not receive admonition unless Allah wills. [Surah Al-Mud-dath-thir. Verses 54-56]

And Allaah’s statement:

فأما من أعطى واتقى وصدق بالحسنى فسنيسره لليسرى وأما من بخل واستغنى وكذب بالحسنى فسنيسره للعسرى

As for him who gives (in charity) and keeps his duty to Allah and fears Him, and believes in Al-Husna; We will make smooth for him the path of ease (goodness); but he who is greedy miser and thinks himself self-sufficient; and gives the lie to Al-Husna, we will make smooth for him the path for evil. [Surah Al-Layl 5-10]

Allaah commanded that one performs actions and to be desirous of it- promised to facilitate good for the one who employs the beneficial means and the one who abandons the beneficial means is abandoned to evil. The Prophet [peace and blessings of Allaah be upon him] said, “Be eager for what benefits you, seek Allāh’s Help and do not be helpless”. This includes being eager for both the beneficial affairs related to the religion and the worldly affairs. Therefore, one knows that the religion of Islaam belies what its enemies fabricate that it is retarded and impotent; rather indeed, it is invigorating and urges towards every beneficial deed, and that belief in Qadr is one of the greatest invigorators towards every beneficial deed and its greatest facilitator. This is why the Prophet [peace and blessings of Allaah be upon him] said, “Act because everyone will be facilitated in that which he has been created for him. Those who are to be blessed (in the Hereafter) will find it easy to do the deeds of those who are to be blessed, while those who are to be among the wretched (in the Hereafter) will find it easy to do the deeds of those who will be wretched’’, then he recited: [فأما من أعطى واتقى وصدق بالحسنى – As for him who gives (in charity) and keeps his duty to Allah and fears Him, and believes in Al-Husna]”. [Surah Al-Layl 5-6]

This is why – in Islam – the one who abandons deeds and relies on Qadr is considered insane and an idiot. Islam disapproved of those polytheists who utilized Allaah’s Divine Decree and Will as a justification for abandoning the beneficial things and informed us that doing so – as excuse – was a practice of the tyrannical nations that were punished with different types of exemplary punishments. There is no beneficial deed – big or small – and the means to it, except that the Lawgiver [Allāh] has urged towards, and that which leads to its perfection (or accomplishment). And there is no harmful deed, laziness and (unpraiseworthy) retreat, except that He has warned against it severely. The texts of the Islamic legislation regarding this fundamental can neither be counted nor enumerated, and whoever rejects it is a haughty individual, confounded and the most misguided of people. [An Excerpt from Ad-Dalaa’il Al-Qur’aaniyyah Fee Annal Uloom Wal-A’maal An-Naafi’ah Al-Asriyyah Daakhilatun Fid Deen Al-Islaamiy. page 31]

Detail Discussion on Belief in Qadaa wal Qadr By Shaikh, Dr Abu Iyaadh, Shaikh Abu Khadeejah and Ustaadh Taqweem Aslam [may Allaah preserve them and all the other Salafi teachers]

http://www.aqidah.com/creed/categories/xy-belief-in-the-divine-decree.cfm
https://www.abukhadeejah.com/al-qadr-no-one-can-escape-the-decree-or-exceed-it/
https://www.salafisounds.com/understanding-qadr-pre-decree-its-levels-the-aqidah-of-imam-muhammad-ibn-abdil-wahhab-by-abu-khadeejah/
http://www.salafipublications.com/sps/sp.cfm?subsecID=AQD09&articleID=AQD090001&articlePages=1
https://www.youtube.com/watch?v=ogoUNuvn14Y
https://www.youtube.com/watch?v=4_qWR6mup0I
https://www.youtube.com/watch?v=bXCkmLu870E