The thing that is specifically offensive about the idea that Jesus is the only way to God is the idea that stems from it that all other religions are wrong, and that unless you have "accepted Jesus as your personal Saviour" you will go to hell. So according to this insane and offensive theology, that means Gandhi and other great luminaries are in hell. (Then there's penal substitution theology, which is also offensive, but that is a separate issue.)
I don't have a problem with the idea of Jesus being divine. I do have a problem with the idea of his being the one and only incarnation of the godhead. As far as I'm concerned, we are all divine.
In polytheist religions, the idea of humans becoming divine, or the divine becoming human, crops up frequently. There's Krishna, who is an incarnation of Vishnu. There's Oðinn, who is either a deified human or a god who became human. There's Aradia, who was Diana's daughter and came to earth to teach Tuscan witches their craft, and how to resist oppression. There are many, many deities who became human, and humans who became deities. So the idea that other religions have a problem with the Incarnation because they don't like the idea of God becoming human is laughably ignorant.
In Judaism, the soul has three components - the nefesh (the animal soul, which disperses at death), the neshamah (the divine part, which returns to God at death), and the ruach (the breath of God, which gives life). The more spiritually developed you are, the greater the neshamah becomes. When Jesus told his disciples that he would send his ruach (his Holy Spirit) to be with the disciples at death, he meant he would send that component of his soul to be with them. This insight must have got lost in the early centuries of Christianity when the Judaic elements were eradicated from Christianity by opponents of "Judaizing". Anyway, the point here is, that in Judaism, everyone is a child of God, and has God within them. (For more on this, see my earlier post, The Trinity and Jewish theology).
In the Religious Society of Friends (the Quakers), they say that everyone has "that of God" within them, and refer to the Inner Christ or the Inner Light. The idea is to uncover that light (not hiding it under a bushel) and let it shine.
In Unitarianism, which rejected the doctrine of the Trinity back in the 16th century, the view is usually that everyone has the Divine within them, too. James Martineau, a great 19th century member of the tradition (who actually identified as a Free Christian), said:
The incarnation is true, not of Christ exclusively, but of Man universally, and God everlastingly. He bends into the human to dwell there; and humanity is the susceptible organ of the divine.What a truly great concept - the incarnation is true of all humans. Or as Shakespeare (religious beliefs unknown) so memorably put it:
What a piece of work is a man, how noble in reason, how infinite in faculties, in form and moving how express and admirable, in action how like an angel, in apprehension how like a god! the beauty of the world, the paragon of animalsIn Buddhism, we all contain the potential to become enlightened, to become a Buddha, to become divine. We are all Future Buddhas.
Hamlet, Act II, Scene II
In Eastern Orthodox Christianity, although they believe that Jesus is the one and only divine incarnation, they also have the concept of theosis, which means that because Jesus opened the way between the human and the divine, we can all become divine. Indeed, Jesus himself said, "I have said, ye are gods."
So, no, the thing that annoys people about the Incarnation is not the idea that God became human - it's the idea that it only happened once.
Everyone has "that of God" within them - the neshamah, the ruach, the seed of a Future Buddha, the potential for theosis.