Oneness of God of different religions
Every religion says that its God created the entire earth and entire humanity. But, unfortunately there is only one earth containing this humanity. Due to one earth, there must be one God only and hence all the religions are calling the same God by different names. Since the God is unimaginable and nobody can even imagine Him, all the names are indicating that unseen and unimaginable God only. This unimaginable God is mediated by energy. Such mediated God is also one and the same because energy is also one and the same for all religions. This mediated God is called as Brahman by Hinduism, Jehovah by Christianity and Allah by Islam. The absolute unimaginable God as well as the medium [Energy] are one and the same and hence there is no difference between these three names.
Of course, when the absolute God gets mediated by human bodies, there may be minute difference in the form, culture and language of the external human form as in the case of Krishna of Hinduism, Jesus of Christianity and Mohammad of Islam. Even here the material of the human body is one and the same except slight variation in the external form. From the point of absolute God, here also there is no trace of difference and hence all these three human forms are also one and the same.