In Deuteronomy, chapter six, verse four, affirms that God is the one true God, not a pantheon of different gods, and is all-powerful among all the gods and spirits of the world, as stated in Exodus fifteen, verse eleven. This verse teaches us about monotheism which means believing that there is only one. The scriptures in Deuteronomy describe the living God in five through nine, chapter eleven, verses thirteen to twenty-one, and Numbers fifteen, thirty-seven to forty-one. This God must be the sole object of Israel’s love and obedience. This aspect of “oneness” is the basis for prohibiting the worship of other gods.
Monotheism does not contradict the New Testament revelation of God as a triune being who, through one, in essence, is manifested as a Father, Son, and Holy Spirit. The words of Moses stirred up the people to attend to what he was about to say about the unity of God to prevent their going into polytheism and idolatry. The doctrine is that the Lord, who was the covenant God and Father of his people Israel, is but one Jehovah. He is Jehovah, the Being of beings, a self-existent Being, eternal and immutable, and one in nature and essence. God appears to the perfection in his character. His eternity, omnipotence, omnipresence, infinity, goodness, self-sufficiency, and completeness. For there can be but one eternal, one omnipotent, one omnipresent, one infinite, one that is original and of himself good. Oneself, all-sufficient, and perfect Being, and also m conclude from his being the first cause of all things, which can be but one, and from his relations to his creatures, as their King, ruler, governor, and lawgiver. And for this purpose, these words are cited in Mark chapter twelve, twenty-nine through thirty. However, they in no way contradict the doctrine of a trinity of persons in the unity of the divine essence, the Father, Word, and Holy Spirit, which three are one.