First conflict arises between different religions, then inside the religion you will see inter religious conflicts arise and then groups are formed. All this happens due to lack of wisdom and lack of understanding.
A wise man would benefit from all religions. He will see that religion is adding more value to one’s life. Without this wisdom if you hold on to religion only for identity and not for your evolution then definitely it is divisive.
Our identity should first be that we are part of one light. The second identity is that we are part of one human society, one global family. And the third could be nationality or language. The fourth could be religion. And fifth could be the heritage or family.
You can keep the other identities, but when you forget that you are a part of one human society, one universal light, that is when religion is used to divide our society and destroy ourselves. With wisdom you would celebrate diversity and take the best from every religion so that you can evolve to be a good human being.