In nature there is a fundamental unity running through all the diversity we see about us. Religions are given to mankind so as to accelerate the process of realisation of fundamental unity.
The major strategy of Satan is to distort the character of God and the truth of who we are. He can't change God and he can't do anything to change our identity and position in Christ. If, however, he can get us to believe a lie, we will live as though our identity in Christ isn't true.