It is lack of contextual understanding of people about fight between kufar and islam. Islam is all about khilaafah=rule of Allah as per his revealed constitution for humanity for its peaceful and prosperous existence here on the earth. It is all about bringing about divine kingdom in to existence. This is opposed by forces that wish to create disorder, trouble, harm and destruction.
It has been always the case that after Allah sent his messengers with laws for people to live by they established divine kingdoms here and there and after their deaths people from among their own followers gradually became distant from following the divine constitutions and instead of ensuring their progress and prosperity they went in to stagnation and regression and some also saw the opportunity to rule others and so fights and wars resulted.
There was a time when system was chnaged from one to the other and as system changed the people who were for divine kingdom were always taken out. Facing such situation they had to go underground to keep their movement going for restoration of khilaafah ie rule by divine constitution. Because these people could not preach islam openly so they relayed this information from person to person in the hope of reviving islamic rule.
Originally this secret movement was genuine but as it was infiltrated by opponents to derail and make it ineffective it became a tool of mullahs for propagating islam as a religion instead of deen.
The difference lies mainly in its approach to God and humanity. It was originally supposed to promote divine kingdom in the world for the good of mankind but instead it became search for God movement.
The truth about God is very clear that man cannot know God because God is beyond human senses and that is al a human has been bestowed with. Therefore it is futile, waste of time and even dangerous for mankind to go this way.
The other approach is from God to mankind ie God revealing himself to mankind the way he can and for the purpose he chooses. This is where come in the divine messengers and books from God.
This means that all ways for approaching God that people claim are false claims and if there is any truth then it lies in the message of God himself. It is for this reason if anyone wants to know anything regarding God then one has no choice but to study his revelations.
If you look at my posts, you will see that I am keep emphasising the study of the quran and the quran itself emphasises the very same. It condemned all other ideas about knowing about God.
It is because people want to know about God without knowing his message, they are in all sorts of troubles and that they are totally confused.
Unless one realises these like major points one is not going to get out of self created delusions and confusions. So my brotherly suggestion is, please get out of all sorts of nonsense and and concentrate heavily on the study of the quran in light of realities of this world. No way you can go much wrong.
Unless a person grows up mentally and becomes mature in reasoning and understanding of the world realities the quran is not going to be of much help. The reason, to understand wisdom you need to be wise enough to benefit from it.