Many people consider that Jesus was a dualist. He talked about a Father and a Holy Ghost as if they were outside himself and represented himself as a Son.
He said his Father was greater than he, even though they were one. He said that the Father had given all things into his hands and sent him out into the world with a task to do.
He said many other things that seemed to suggest that the Father existed as an objective reality from which he, Jesus, was somehow separate. And yet he was the Son of that Father and sent on a mission, etc.
But let us examine the situation a little more deeply. 
Hindu Advaita (non-dual) Vedantists (explicators of the non-dual Upanishads or Vedanta) are looked upon as non-dualists. They speak of Brahman, Atman, and Maya or Shakti. Brahman is the only Reality and is mysteriously individuated as Atman, or Brahman-within-the-individual. All of us are illusory forms, created by Maya or Shakti, the energy of Brahman. Shakti differs from Brahman as movement differs from rest, sound from silence, and form from formlessness.
Are we agreed?
Well, I contend that what Vedantists called Brahman, Jesus called the Father; what Vedantists called Atman, Jesus called the Son; and what Vedantists called Maya or Shakti, Jesus called the Holy Ghost. Put in equation form, Father, Son and Holy Ghost = Brahman, Atman, and Shakti. Jesus spoke of a Holy Family but in actuality he only spoke of the same three levels of Reality that the Advaitins spoke of.
If Vedantists are non-dualists, why is not Jesus so considered? Do different names make any difference? I don’t think so.
When Jesus said “I am the truth, the way, and the life,” in my opinion, he did not mean “I, Jesus.” He meant the I, the Self, the individuated Brahman, which he called the Christ, the Savior, the Prince of Peace.
Of course the I, Self, or Atman is the Savior. Knowledge of the Self brings salvation, liberation, redemption from physical birth and death. But it must be known as one with the Father. It is the Prince of Peace because perfect knowledge of it does bring peace, a peace which passeth understanding.
This Atman or Christ is seen in a moment of enlightenment and is known to be the “truth.” Meditation on it is the “way” to knowledge of Brahman or the Father. And that knowledge, when perfected, leads to “life,” by which he meant not needing to go more out of the temple; i.e., liberation from the need to leave the higher realms and be reborn into this realm of matter, mater, Mother or Shakti, the Holy Ghost.
To illustrate that “I am the way, the truth, and the life,” he gave parable after parable, all of which say the same thing. A man (woman, child) was digging in a field (the body), came across a great treasure (in the heart), buried it up again, went away, collected all his wealth, sold it, and bought the field. A man (woman, child) saw a pearl of great price, went away, sold all that he had, and bought the pearl. A man put a measure of meal in a loaf and it leavened the whole loaf. A man planted a mustard seed and it grew into a great tree. They all say the same thing. They tell us how to get to God, how to realize Brahman or the Father, etc.
Jesus knew that his generation would as a whole not use his knowledge well and so he hid his wisdom in parables.
Let’s look at one of these.
A man was digging in a field….
A person was practicing spiritual disciplines, in the haphazard way that we all do, meditating one day, forgetting to meditate the next day, carousing, having a spiritual discussion….
… when he came across a great treasure…
When he saw the light of the Atman or Christ, at a time of God’s own choosing. When the kundalini energy rose to the Fourth Chakra he saw a discrete point of light, which we know as the Self, the Atman, the Son of God or Christ.
… he covered up that treasure…
He reflected on that experience and resolved to become more focused in his practice.
… he went away and sold all he had….
The sight of the Atman, Self, or Christ ceased and the man wanted it back. He began to practice spiritual discipline in a far more focused manner. He let go of all other desires than owning the treasure of the sight of the Atman, Self, or Christ. He began to meditate exclusively on the Light he had seen.
… and returned and purchased the field.
After many days, weeks, months, and perhaps years of meditating exclusively and constantly on the discrete Light, it grew into a Light that transcended creation, transcended form, transcended everything he knew as reality. In an experience called sahaja (or permanent) nirvikalpa samadhi, he realized a Light that transcended creation or form and this time it did not leave him.
Perhaps a seeker does not meditate but follows another path, such as service or devotion. But the following of whatever path he takes becomes more focused and concentrated.
The Son has now “led” the seeker to the Father. Atman has become Brahman. I and the Father are One. The truth has provided a way to the life. The “I” of the Atman or Christ has shown itself to be the truth, the way, and the life – the truth of the Father, the way to the Father, and the life afforded by permanent knowledge of the Father.
Nothing I have said yet shows Jesus to have been a dualist, but a non-dualist.
Perhaps someone among readers had a question about this. Perhaps someone wanted to know how the teachings of Jesus are consistent with what all other religions are saying. Perhaps someone said how can I be a Christian and read the rest of the material on this website? I don’t know.
But there it is. In my view, Jesus was as much a non-dualist as Krishna. And as much a dualist since dualism is in reality simply an earlier view of spirituality than non-dualism, just as Grade 6 is an earlier view than Grade 7. Dualism is contained in Non-Dualism, as we see here.
Yes, there is only one God and the One has become the many. No, Jesus did not deny non-dualism and set up a dualistic path in contradistinction to non-dualism by recognizing a Father, a Son, and a Holy Ghost. Yes, Christianity and Hinduism say the same thing in different words. And the same could be said for Christianity and Buddhism, Islam, Taoism, etc.
There is a Perennial Philosophy, an ancient wisdom, a fount of spirituality underlying all religions which is the source of all teachings. There is a Reality which all great teachers contemplate, realize, and then find their own unique way of describing. Words are different but Reality is the same. Jesus was as much a non-dualist as any of the rishis.