“Hear, O Israel: The Lord our God, the Lord is one.”
As we have seen over the past few days, the doctrine of the Trinity is an essential part of the Christian faith, indeed, of the biblical gospel. The Apostles’ Creed, being a concise summary of the work of the Trinitarian Creator on our behalf, is therefore an excellent presentation of gospel truth. Yet when we begin talking about the Trinity, we are entering into one of the deepest mysteries of the Christian faith. After all, with finite minds we are considering the nature of the infinite God Himself. We are treading on holy ground.
Nevertheless, although the Trinity is a mystery we will never fully understand, the fact that it is a mystery does not mean that we cannot understand it at all. God has revealed Himself in His Word, and He has sent His Spirit to illumine our minds and give us understanding of this Word (1 Cor. 2:6–16; 2 Tim. 3:16–17). Therefore, we can say much about the Trinity even if this biblical doctrine tells us that the Creator is far more complex than any of us can imagine.
In question and answer 25 of the Heidelberg Catechism, we are told that Christians speak of three persons in the one Godhead because that is how Scripture reveals this truth. We begin first with the biblical affirmation of monotheism. From Genesis to Revelation, the Bible is clear that there is but one God who alone is to be worshipped and served without hesitation. Today’s passage is perhaps the clearest statement of this fact. Deuteronomy 6:4 does not simply mean that there is one God for Israel but that there is only one God, period. Nothing else in existence is equal to Him in any way, not even human beings, who are more like the Creator than anything else in His creation (Gen. 1:26–27). He alone has created all things. He alone is independent and in need of nothing. He alone is underived from any plan, person, or substance. He is the Lord and there is no other (Deut. 4:39; Isa. 45:5).
We likely take the confession of Christian monotheism for granted, so it is easy to forget its practicality. Monotheism means that we do not have to worry about another god clobbering the One whom we serve or snatching us away from Him. Monotheism means that God can meet all our needs because He needs nothing from any other source. Let us understand that God is one, and let us therefore rejoice.
Coram Deo
Christian monotheism is vastly different from the monotheism found in Islam and modern rabbinic Judaism. We are not unitarians who simply have a different name for the same God others worship. Those who deny the Trinity deny the deity of Christ and of the Holy Spirit and, thus, deny the one true God. Monotheism alone is not enough for salvation. Only believing in the right God grants us access to heaven. We must always be clear on this precious truth.