To Protestants, Catholics are giving undue reverence that possibly borders on blasphemy to a human institution, and placing human authority over God. To Catholics, Protestants are heretics who have cut themselves off from the only true path to God and are in rebellion against the successors of Christ's Apostles and His designated representatives on Earth. And that is without even getting into the doctrinal differences. To Muslims, all Christians are guilty of idolatry for worshipping a man, a mere prophet, as God. To Muslims & Jews, Christians are committing blasphemy and idolatry by claiming that Jesus is God, while to Christians, Muslims and Jews are guilty of the same by denying the Divinity of Christ and by slighting Him. These are huge, irreconcilable differences and attempting to gloss over them by talking up trivial similarities is a ludicrous waste of time. As long as none of us are forcing each other to worship a certain way or preventing each other from engaging in the free exercise of our respective religions, that is good enough.