We Christians believe in one God who has no partner. He is infinite, filling the heavens and the earth. He is the creator of all, eternal, and everlasting. His kingdom is without end.
This creed is very clear in the holy Gospel. The Christian canon of belief is what follows:
1. The Lord Jesus Himself taught this belief when a Jew came to ask Him about the greatest commandment. He answered him, "Hear, O Israel; the Lord our God is one Lord; and you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength" (Mark 12:29-30). This is the first commandment. If this commandment had been written in the language of the Qur'an, it would have been "God, our God, is the only (unique) God, the everlasting God."
2. The apostle Paul clarified this saying, "Is God just for the Jews and not for Gentiles as well? Yes, for Gentiles also because God is one" (Romans 3:29-30).
3. And the apostle James expressed the same belief saying, "You believe that God is one. You do well" (James 2:19).
4. The Christian creed was taken from these texts along with others in the Bible. The Church has been avowing these beliefs for generations saying, "Truly we believe in one God... Creator of heavens and earth, and the visible and invisible." Hence, my dear friend you perceive that we Christians believe in one God and not three gods. We shall clarify the meaning of the Father, the Son, and the Holy Spirit in the discussion about the holy Trinity of Christianity.
THE HOLY TRINITY IN CHRISTIANITY
The doctrine of the holy Trinity in no way means the existence of three gods as some people wrongly imagine. The meaning of this doctrine is - God is one...
Existing in Himself, so He declared Himself as
Speaking His word, so He declared Himself as
the Son, the Word,
Alive in His spirit, so He declared Himself as
the Holy Spirit.
It should not be understood from these names that there is a bodily relationship as in human terms, but rather it has a spiritual meaning.
These names are not established or invented by man, but they are the words of divine inspiration in the Holy Book, as you will see from the following references:
1. The Lord Jesus said to His disciples, "Go therefore and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit." (Matthew 28:19) Monotheism is clear in His words, "baptizing them in the name." He did not say "baptizing them in the names of the Father, the Son and the Holy Spirit."
2. The apostle John very clearly confirms this understanding. "Those who testify in heaven are three, the Father, the Word, and the Holy Spirit and these three are one" (I John 5:8).
When comparing the two verses, you find the names of the holy Trinity: the Father, the Son and the Holy Spirit. This is the holy Trinity in the only God in whom we believe.