From Volume 8 of The Complete Works of Swami Vivekananda, chapter -III, ‘Notes Of Class Talks And Lectures’

Jesus Christ was God — the Personal God become man. He has manifested Himself many times in different forms and these alone are what you can worship. God in His absolute nature is not to be worshipped. Worshipping such God would be nonsense. We have to worship Jesus Christ, the human manifestation, as God. You cannot worship anything higher than the manifestation of God. The sooner you give up the worship of God separate from Christ, the better for you. Think of the Jehovah you manufacture and of the beautiful Christ. Any time you attempt to make a God beyond Christ, you murder the whole thing. God alone can worship God. It is not given to man, and any attempt to worship Him beyond His ordinary manifestations will be dangerous to mankind. Keep close to Christ if you want salvation; He is higher than any God you can imagine. If you think that Christ was a man, do not worship Him; but as soon as you can realise that He is God, worship Him. Those who say He was a man and then worship Him commit blasphemy; there is no half – way house for you; you must take the whole strength of it. “He that hath seen the Son hath seen the Father”, and without seeing the Son, you cannot see the Father. It would be only tall talk and frothy philosophy and dreams and speculations. But if you want to have a hold on spiritual life, cling close to God as manifest in Christ.

Philosophically speaking, there was no such human being living as Christ or Buddha; we saw God through them. In the Koran, Mohammed again and again repeats that Christ was never crucified, it was a semblance; no one could crucify Christ.

The lowest state of philosophical religion is dualism;
the highest form is the Triune state. Nature and the human soul are interpenetrated by God, and this we see as the Trinity of God, nature, and soul. At the same time you catch a glimpse that all these three are products of the One. Just as this body is the covering of the soul, so this is, as it were, the body of God. As I am the soul of nature, so is God the soul of my soul. You are the centre through which you see all nature in which you are. This nature, soul, and God make one individual being, the universe. Therefore they are a unity; yet at the same time they are separate. Then there is another sort of Trinity which is much like the Christian Trinity. God is absolute. We cannot see God in His absolute nature, we can only speak of that as “not this, not this”. Yet we can get certain qualities as the nearest approach to God. First is existence, second is knowledge, third is bliss — very much corresponding to your Father, Son, and Holy Ghost. Father is the existence out of which everything comes; Son is that knowledge. It is in Christ that God will be manifest. God was everywhere, in all beings, before Christ; but in Christ we became conscious of Him. This is God. The third is bliss, the Holy Spirit. As soon as you get this knowledge, you get bliss. As soon as you begin to have Christ within you, you have bliss; and that unifies the three.