The essence of Religion, (that is of the Science of Correct Human Behaviour and Government) is to replace base human urges (that is, the Whisperings of the Devil) with rational behaviour beneficial to Man as individual and as a species (that is, with God's Guidance).
But, this science has developed in different ways among different human groups, and this is why there are many "religions" and sects within these "religions", and this is why there are differences.
Some of these differences relate to the understanding of the World (the religious theories), and other to rituals and organisational structures.
No human group holds the monopoly of Right and Wrong, and no human is infallible. And no human group owns God. But, some beliefs held by humans are right and others are wrong, and some rituals and organisational structures are more effective than others, and still others are just as good, but different, and still others are suitable for one geographical area and unsuitable for other.
And it is to the benefit of all, collectively, and each, individually, to seek what is right and what is better on its merits, rather than hold onto, or seek to impose on others, beliefs and rituals merely because they happen to be "ours", even if they happen to be wrong or inferior to "theirs".
Nor is it beneficial to anybody to "compromise" and accept what is wrong, to please others, because in such case both the parties will be the losers.
It should also be understood that the present spread of immorality is due not to those who "follow the Devil", but to the failing of the religious leaders themselves (past and present) to seek God's Guidance on the problems of their time and to guide Mankind along the God's Path.
It is this failing that has lead to the emergence and pre-dominance of Political Ideologies and the Moral Vacuum which we witness today.
One should not seek to "convert" the rest to one's own ways, because they happen to be one's own, but reject what is wrong, and accept what is right and better regardless of from where it comes.
And, if one's own ways happen to be right while others' to be wrong, then one should explain it to the others in a calm, factual, friendly way and with respect to their history, culture and traditions, rather than seeking to impatiently force it on others, or act towards them in hostile ways.
But, if the "other" tell that one is wrong, one should not feel "offended" and become "defensive", or "turn away", or "walk out", but should consider the "accusation" rationally and logically, and, if "they" happen to be right, accept what is right with gratitude, and, if "they" are wrong, then be grateful to the "accuser" for providing an opportunity to demonstrate that one is right.
In the end there is only one true religion - the Science of the Correct Human Behaviour and Government, and this religion belongs to no man, but to God.