It is a good thing to want to believe that we are worshiping the same God under different names. We perhaps say this because of a noble desire that all people should be united instead of divided.
Indeed, the beliefs of various religions originated among different cultures and times. They all reveal the need and desire that human beings have for worshiping something greater than themselves. For Christians, the starting point is to ask WHY do we have this need and desire to worship God? What is it within us that is driving us to do this?
In ancient times, human beings created their own gods in order to explain and give meaning to what they were experiencing in life, whether that was good things or bad things, life or death. If they had a plentiful harvest and food to eat, they praised the sun and the rain as gods. If there was a drought and hunger, they felt a need to appease these gods through sacrifices (animal or even human sacrifices) so that it would rain again. For example, the name “Hindu”, comes from the name of the Indus river, which was a vital source of life and well being for the people living near it. Their dependence on the river naturally inspired a sacred devotion to it, the same way the Aztecs had a devotion to the Sun.
We also need to remember that various cultures and people have very different definitions and understanding of what ‘god’ means. Is God a being? Is he a spirit? Is he a concept? Is he a force? Is he a person? A Hindu would answer these questions differently than a Christian. A Hindu would say that there is a Ultimate Reality (Brahman) who is a kind of force and all other Hindu gods are just aspects of this force. According to this line of thought, the gods of Hinduism are not truly beings but forces. Engaging with them means experiencing a force. However, a force does not have true being. It is a bi-product. It cannot exist on its own. It must originate from something else that is greater than itself. Wind energy is a force that can only exist because of the wind that generates it.
A Christian will say that God is not definable by human beings. He is above all names, ideas, images, labels, categories and descriptions. Anything we might say about God is still something that is limited and confined by our own imagination and vocabulary. Rather, we can only go by what God has revealed about himself both in the power and beauty of the universe and as recorded in the Holy Bible.
For a Christian, God is neither a force nor a being. If he was a force then that force must have an origin and therefore He cannot be God since that means he was created. If he was a being, then again that means he was created by another greater being and cannot be truly God. Neither can he have a name because that means someone named him. Instead, we say that God is the Primordial Cause. The origin of all things who himself is without origin. He exists both outside of time and within time. He is past and present and future. He is everywhere and in all things because nothing can exist apart from him since only He has true existence and true life. In one passage in the Holy Bible he is asked what his name is and he answers, “I Am” (Exodus 3:14). In other words, he alone has true existence.
God is both outside of us and within us. He is both unapproachable and at the same time intimately a part of us because we are made in his “image and likeness” (Genesis 1:26). It is a mystery and a paradox. God is like the Sun. We can never land on the Sun but neither can we live without it. We can never touch it yet its warmth and its rays penetrate through our bodies. Just as every atom that is found in the universe outside of us is also found within us so God is both outside of us and within us.
If you read the Holy Bible, you will see that it is a record of how God reveals himself to human beings as being completely unapproachable and indefinable yet at the same time as a loving, compassionate, merciful and kind Father, a person, with whom we can have a relationship and intimate human contact or what we call Communion. In order for God to do this, it was necessary for Him to interact with us in a way that we can comprehend and experience at a human level. Otherwise, he would always remain someone distant and unapproachable. In order for us to have a relationship with him, to know him, to fully experience his love, kindness and friendship, he had to become a human being himself. He had to come down to our level. This is the person of Jesus Christ who was both God and Man. This condescension of God is what we rejoice over and celebrate on Christmas. Jesus Christ is the human face of God. The love of Christ who was willing to suffer death in order to save humanity reveals the love that God has for all of us.
The people who wrote the Holy Bible described what they heard, saw and experienced themselves. They were not enlightened people but eye-witnesses. The saints even have experiences of seeing Christ to this day along with many miracles that occur for those who have true faith.
For human beings, our greatest enemy is Death and the one who held the power of death, that is, the Devil. The God-Man Jesus Christ was crucified and died and he rose from the dead after three days. He truly died because he was a human being. But he truly rose from the dead because he was God and death could have no power over him since God is Life itself. There were hundreds of eyewitnesses who saw him resurrected. They were even killed for refusing to stop sharing with others what they heard and saw from Jesus Christ. Christianity spread like wildfire because so many miracles accompanied the teachings of the followers of Christ. It grew so much that even the Roman Empire which had carried out the crucifixion of Jesus and who used to believe in hundreds of gods also became Christian within a few hundred years.
By being resurrected from the dead, Christ gave all of humanity victory and power over Death and the Devil as well. For Christians, death is no longer the end but a door to eternal life with God in the new world. Instead of being reincarnated, we retain our total identity as human beings, because by being joined to the God-Man Jesus Christ, we are joined to God the Eternal Truth, and truth is absolute and cannot change. This is why Christ says, “I am the Way, the Truth, and the Life, no man comes unto the Father but by me” (John 14:6).
This relationship with God is something we were created to enjoy, something that we had in the beginning but which was lost. Christianity is about the restoration of this relationship between humanity and God the Father and the reclaiming of our original identity. Just as we are all human beings and every one of us has their own singular biological father here on earth, so we are all united and one because we are all children of the one true God, our Father in Heaven.