When studying 'Aqidah, you need to learn things from the ground up.
Meaning: you need to start at the very basics; making sure that you understand each point before moving forward. Doing this will ensure that you've built a solid foundation, which will prove to be essential later on. Without a solid foundation, you've left room for misguidance and misconceptions (shubuhat) to slip into your 'Aqidah and beliefs.
Think about it like this: if you're building a house, you'd make sure to build it on solid ground. Why? Because there's a good chance the house might collapse on itself if the ground beneath it is unstable. Likewise, you could think of these fundamentals in 'Aqidah as pillars, holding up all other Islamic sciences. If there's a mistake in your understanding of the shahadah, then all of the other sciences will collapse, rendering it all meaningless on the Day of Resurrection.
Allah (تعالى) says about those who disbelieved:
{ وَقَدِمْنَآ إِلَىٰ مَا عَمِلُوا۟ مِنْ عَمَلٍۢ فَجَعَلْنَـٰهُ هَبَآءًۭ مَّنثُورًا }
"Then We shall turn to the deeds they have done and reduce them to scattered dust." [Surah al-Furaq, 23]
And what is worse than doing all of this 'ibadah, studying the religion, and sacrificing so much, when in the end a mistake in your 'aqidah caused you suffering in the akhirah. Just as He (سبحانه وتعالى) said:
{ قُلْ هَلْ نُنَبِّئُكُم بِٱلْأَخْسَرِينَ أَعْمَـٰلًا * ٱلَّذِينَ ضَلَّ سَعْيُهُمْ فِى ٱلْحَيَوٰةِ ٱلدُّنْيَا وَهُمْ يَحْسَبُونَ أَنَّهُمْ يُحْسِنُونَ صُنْعًا }
"Say, [O Muḥammad], 'Shall we [believers] inform you of the greatest losers as to [their] deeds? Those whose efforts have been wasted in this life while they thought that they were acquiring good by their deeds'" [Surah al-Kahf, 103-4]
Many of those who went astray, such as the different Jahmi sects - those who claim the most disgusting and vile things about Allah's beautiful Names & perfect Attributes, the modern day madakhila - those who excuse shirk with ignorance and only declare takfir when kufr is uttered upon the tongue, the modern day ghulat - those who declare takfir upon Imam bukhari and Shaykh al-Islam ibn taymiyyah, and all of the other deviant groups - all of them started from a major errors in the 'Aqidah of their leaders.
So, my Muslim brother, don't rush this knowledge. For by Allah, it is of the utmost importance.
@AbuDhar1
