I (God) could have made the entire mankind born into one community, one tribe and one nation

But I (God) did not do that

Had your Lord so willed, He would have certainly made humanity one single community ˹of believers˺, but they will always ˹choose to˺ differ – Quran 11.118

I (God) wanted to check not how religious you are
but how conscious you are despite religious divisions

The prophets I (God) sent did not preach religions but humanity

I (God) manifested you (man) in this world not to preach your religion to another and convert people

Not to tell my Allah is greater than your God and to  say my Muhammed (pbuh) is special than your Jesus (pbuh)

That was not the task given to you
The task entrusted to man is to know God
The task entrusted to man is to REALIZE him (God) within man

Your task of man in this world is not to correct anybodys religion

God (Allah) did not create you to correct others belief 

Allah did not create you to worry over his tasks

Correcting others, converting others to embrace Islam, arguing and quarreling to prove you are correct, raising awareness (Dhawwa) about Allah, his messenger, about Quran is not the task entrusted to you

Allah did not create you to worry or feel anxiety over his tasks

The duty of the follower is to know him (God) within you

Your task in this world is to be the instrument of the divine and to bring love, harmony and Allah’s (Gods) beauty in to this world

Always remember, the creator is within you
You are his instrument
and through you, He (God) display HIS beauties to the external world