This excerpt is taken from Sheikh al-Islam Imam Ibn Taymiyyah's book Al-Jawab al-Bahir fi Zuwar al-Maqabir, translated by Sheikh Ataullah Saqib.
(The Strong Advice of Imam Ibn Taymiyyah)
It is incumbent upon the ruling class that they commit themselves to the Sunnah of the Messenger of Allah, peace be upon him, and the support of the true religion, and enforce it upon the people. They should eliminate those matters from which people have been forbidden and eradicate the slanders, falsehoods, and innovations of the grave worshippers that have been introduced into the Shariah, whether intentionally or out of ignorance and lack of knowledge.
The essence of Islam is that the great and important duty of enjoining good and forbidding evil be put into practice. Tawhid (monotheism) is the root of goodness, and shirk (polytheism) is the extreme of evil. The Messenger of Allah, peace be upon him, was sent with the true religion and guidance, who clarified the difference between tawhid and shirk. He guided to distinguish between truth and falsehood, and established a boundary between guidance and misguidance, between good and evil.
Now, whoever wants to reverse enjoining good and forbidding evil, and desires to alter Islam and the pure Shariah, whether out of ignorance or worldly greed, and commits this reprehensible act, it becomes obligatory upon the ruler of the time to silence such people and expend his strength in supporting and assisting the Book and Sunnah, because the Almighty Lord has firmly promised that He will assist His messengers and the believers in this world and the Hereafter. So whoever is fortunate enough to assist Islam will be successful and honored in this world and the Hereafter.
Otherwise, Allah is capable of taking the service of His religion from any other person and then rewarding each person according to their deeds and character, for it is the attribute of the Almighty Lord that وما ربك بظلام للعبيد (Your Lord is not one to wrong the servants).
And Allah has promised to support the truth, and about the one who tries to turn away and neglect the truth, the Almighty Lord says:
يَا أَيُّهَا الَّذِينَ آمَنُوا مَا لَكُمْ إِذَا قِيلَ لَكُمُ انفِرُوا فِي سَبِيلِ اللَّهِ اثَّاقَلْتُمْ إِلَى الْأَرْضِ ۚ أَرَضِيتُم بِالْحَيَاةِ الدُّنْيَا مِنَ الْآخِرَةِ ۚ فَمَا مَتَاعُ الْحَيَاةِ الدُّنْيَا فِي الْآخِرَةِ إِلَّا قَلِيلٌ ﴿٣٨﴾ إِلَّا تَنفِرُوا يُعَذِّبْكُمْ عَذَابًا أَلِيمًا وَيَسْتَبْدِلْ قَوْمًا غَيْرَكُمْ وَلَا تَضُرُّوهُ شَيْئًا ۗ وَاللَّهُ عَلَىٰ كُلِّ شَيْءٍ قَدِيرٌ ﴿٣٩﴾
“O you who have believed, what is [the matter] with you that when you are told to go forth in the cause of Allah, you cling heavily to the earth? Are you satisfied with the life of this world rather than the Hereafter? But what is the enjoyment of worldly life compared to the Hereafter except a [very] little. If you do not go forth, He will punish you with a painful punishment and will replace you with another people, and you will not harm Him at all. And Allah is over all things competent.”
Reference: (9-At-Tawbah:38-39)
يَا أَيُّهَا الَّذِينَ آمَنُوا مَن يَرْتَدَّ مِنكُمْ عَن دِينِهِ فَسَوْفَ يَأْتِي اللَّهُ بِقَوْمٍ يُحِبُّهُمْ وَيُحِبُّونَهُ أَذِلَّةٍ عَلَى الْمُؤْمِنِينَ أَعِزَّةٍ عَلَى الْكَافِرِينَ يُجَاهِدُونَ فِي سَبِيلِ اللَّهِ وَلَا يَخَافُونَ لَوْمَةَ لَائِمٍ ۚ ذَٰلِكَ فَضْلُ اللَّهِ يُؤْتِيهِ مَن يَشَاءُ ۚ وَاللَّهُ وَاسِعٌ عَلِيمٌ ﴿٥٤﴾
“O you who have believed, whoever among you should revert from his religion - Allah will bring forth [in place of them] a people He will love and who will love Him [who are] humble toward the believers, powerful against the disbelievers; they strive in the cause of Allah and do not fear the blame of a critic. That is the favor of Allah; He bestows it upon whom He wills. And Allah is all-Encompassing and Knowing.”
Reference: (5-Al-Ma'idah:54)
The Lord of Glory has shown people this pattern as a mirror to their own souls and to others, how He confirms His commands and decrees. Referring to this, the Almighty Lord says:
سَنُرِيهِمْ آيَاتِنَا فِي الْآفَاقِ وَفِي أَنفُسِهِمْ حَتَّىٰ يَتَبَيَّنَ لَهُمْ أَنَّهُ الْحَقُّ ۗ أَوَلَمْ يَكْفِ بِرَبِّكَ أَنَّهُ عَلَىٰ كُلِّ شَيْءٍ شَهِيدٌ ﴿٥٣﴾
“Soon We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth. But is it not sufficient concerning your Lord that He is, over all things, a Witness?”
Reference: (41-Ha Mim As-Sajdah:53)
والله أعلم
والحمد لله رب العالمين