Sadly, in this era, many of those who invite others to Islam do not give importance to the subject matter of ʿaqīdah (creed) nor its rectification. In fact, some of them may proclaim: “Be permissive of all the different creeds and beliefs; do not concern yourself with them! Be a means of unity, not splitting… Let us unite in our matters of agreement, and excuse one another in our contentious matters of controversy”¹, and similar statements which oppose Allāh’s—the Most High—saying:

يَا أَيُّهَا الَّذِينَ آمَنُوا أَطِيعُوا اللَّهَ وَأَطِيعُوا الرَّسُولَ وَأُولِي الْأَمْرِ مِنكُمْ ۖ فَإِن تَنَازَعْتُمْ فِي شَيْءٍ فَرُدُّوهُ إِلَى اللَّهِ وَالرَّسُولِ إِن كُنتُمْ تُؤْمِنُونَ بِاللَّهِ وَالْيَوْمِ الْآخِرِ ۚ ذَٰلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلًا

“O’ you who have believed, obey Allāh and obey the Messenger and those in authority over you. And if you disagree among yourselves over anything then refer it back to Allāh and the Messenger if you truly believe in Allāh and the Last Day. That is better (conduct) and (leads to) the most excellent outcome.”
(Al-Nisāʾ, 4:59)

The empowering of the Muslims and their unification shall never occur until they return to acting in accordance with the Book of Allāh, the Sunnah of His Messenger (صلى الله عليه وسلم), abandoning what opposes them particularly in the fundamental matters of creed,.

The Most High said:

وَاعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا وَلَا تَفَرَّقُوا

“Hold fast to the rope of Allāh, altogether, and be not divided among yourselves.” (Āl-ʿImrān, 3:103)

Truly, the latter generations of this ummah will not be rectified except by that which rectified its earlier generations [i.e., the Qurʾān and Sunnah].²

Endnotes:

[1] For further reading: An Exposition Of The Ikhwāni Principle Of Excusing Differences For The Sake Of Unity by Shaykh Abū Khadījah.
[2] Al-Irshād Ilá Ṣaḥīḥ al-Iʿtiqād: 7.