Christians and Muslims are actually cousins

In fact, Christians and Muslims are actually cousins because both are the two branches of same ancestor Abraham. One branch was headed by Ishmael, which became Islam. The other branch headed by Isaac became Christians. Muslims recognize Jesus also as the precedent prophet to Mohammad. Mohammad was very much pained at the crucifixion of Jesus and hence resisted the concept of human incarnation, which can never be relished by the co-human beings due to ego and jealousy. This is not difference of policy but it is due to the heart felt pain by Mohammad about Jesus.

Hindus were always co-operative with every religion and you can find the peaceful co-existence of Christianity and Islam in India with out any violence. In fact, Hinduism itself is a mini model of Universality of Religions. There are several sub-religions in Hinduism like Shaivism, Vaishnavism, Shaktayism etc., which co-existed based on unity in diversity. In fact, Shankara co-related all the sub-religions and brought the unity based on single God called Brahman appearing in different forms like Shiva, Vishnu, Shakti etc.

The same process of unity of religions in one region was carried on by Mohammad, who established the concept of single God called as Allah. Of course, Shankara brought such unity by powerful logic and debate, where as Mohammad brought the same unity through powerful sword. The powerful knowledge is represented by sharp sword as said in Gita [Chchittvaa jnaanaasinaa