Exodus 20 – verse 4: You shall not make for yourself an idol in the form of anything in heaven above or on earth beneath or in the waters below. You shall not bow down to them or worship them for I, the Lord God, am a jealous God.
I agree you should not put other peoples religions down, but someone who is christian is not narrow minded for only believing in one God, they are obeying the law of God.
Also the people who do not believe in Christ, the people who think the world and universe appeared by accident, are spiritually blind. They try to win the world but lose they’re soul.