There are two fundamental ways of viewing religion: From the perspective of the Divine Unity, and the perspective of this world of distinction. Each perspective has its own truth. In the realm of Unity, the Founder of each religion is compared to the Sun: whatever season it may be on Earth, the Sun is unchanged by it. Any differences witnessed are due to the orientation of the Earth, and not the Sun.
When I think of other religions, I examine them according to this unity. Their differences are due to the varying needs of humankind as it has developed. But their inner reality is one and the same. Bahá’u’lláh wrote:
If thou be of the inmates of this city within the ocean of divine unity, thou wilt view all the Prophets and Messengers of God as one soul and one body, as one light and one spirit, in such wise that the first among them would be last and the last would be first. For they have all arisen to proclaim His Cause and have established the laws of divine wisdom. They are, one and all, the Manifestations of his Self, the Repositories of His might, the Treasuries of His Revelation, the Dawning-Places of His splendour and the Daysprings of His light. Through them are manifested the signs of sanctity in the realities of all things and the tokens of oneness in the essences of all beings. Through them are revealed the elements of glorification in the heavenly realities and the exponents of praise in the eternal essences. From them hath all creation proceeded and unto them shall return all that hath been mentioned. And since in their in most Beings they are the same Luminaries and the self-same Mysteries, thou shouldst view their outward conditions in the same light, that thou mayest recognize them all as one Being, nay, find them united in their words, speech, and utterance.
In this light, all other religionists are my brothers and sisters, and I always look to find the points of unity between their Faith and mine. Even if time or differences in language have obscured it, it is always there.