One of the hardest things to grasp about the nature of the one God of Israel is the New Covenant doctrine of the Trinity. It has long been a stumbling block, especially for my Jewish friends, who often ask me: “Doesn’t the Shema clearly say, ‘Hear, O Israel! The LORD our God, the LORD is one’ (אֶחָד, echad)? Then how can God be one and three at the same time?” It is an important question because both Jews and Christians believe there is only one true God. Rather than beginning with a theological definition, I usually respond with a question of my own.
What happens to sunlight when it passes through a prism?
Most people know the answer. White light separates into the familiar spectrum of colors. Then I ask another question. Is the red light still light? They answer yes. The orange light? Yes again. The yellow? Green? Blue? Violet? Yes to each. As we think through the illustration, it becomes clear that white light may appear to our eyes either as a single beam or as a diversity of colors, depending on how it is viewed. Yet whether perceived as one or many, it remains light.
The comparison, of course, has limits. Light belongs to the created universe, while God is the uncreated Creator. No illustration drawn from creation can explain the nature of the One who created all things. Nevertheless, the analogy helps us understand one important principle: a single reality can be perceived in more than one way without becoming multiple realities.
Something similar happens in Scripture.
The God who revealed Himself to Moses declared, “Hear, O Israel: The LORD our God, the LORD is one.” Christians affirm that declaration without reservation. Yet as God’s revelation unfolds throughout the Scriptures, Christians believe that the B’rit Hadashah (New Covenant Scriptures) reveals more fully what had always been true: the one God of Moses initially revealed in the Tanakh has eternally existed as Father, Son, and Holy Spirit.
This is not a change in God’s nature but a fuller revelation of the One who has always been. The New Covenant, foretold centuries earlier in Jeremiah 31:31–34, brings with it a fuller revelation of the God who established that covenant.
It is impossible for finite human beings to comprehend fully the nature of an infinite God. His being transcends space, time, matter, and every other created category by which we attempt to understand reality. The doctrine of the Trinity is therefore not something we can explain completely; it is something God has progressively revealed about Himself so that we may know Him more fully and understand more accurately who He is.
The prism illustration does not explain the Trinity. Rather, it helps remove the assumption that unity and plurality are necessarily contradictory. Just as light can appear both as white and as a spectrum of colors without ceasing to be light, so the one God can reveal Himself as Father, Son, and Holy Spirit without ceasing to be one God.
Every analogy of God ultimately breaks down because every analogy is drawn from the created order, while God is the uncreated Creator. The purpose of an analogy is not to totally explain God’s essence but to remove unnecessary objections so that we may receive what God has chosen to reveal about Himself.
The B’rit Hadashah summarizes this mystery in these words: “There are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one” (1 John 5:7). Christians therefore do not worship three gods. They worship the one God who has revealed Himself as Father, Son, and Holy Spirit.
There is also an important distinction between a contradiction and a mystery. A contradiction claims that something is not the same thing in the same respect at the same time. The doctrine of the Trinity makes no such claim. It does not teach that God is one Person and three Persons. Rather, it teaches that God is one Being who eternally exists as three Persons. We cannot fully comprehend how that can be so, but that is very different from saying it cannot be true.
Christians do not believe in a different God from the God of Abraham, Isaac, and Jacob. They believe that the one God of Israel has progressively revealed more fully the eternal nature of His own being as Father, Son, and Holy Spirit.
Ultimately, the doctrine of the Trinity is a divine mystery to be received with humility, faith, and worship. As Isaiah reminds us, “For My thoughts are not your thoughts, nor are your ways My ways,” says the LORD. “For as the heavens are higher than the earth, so are My ways higher than your ways, and My thoughts than your thoughts.” (Isaiah 55:8–9)
The Meaning of Echad
The Hebrew word ‘echad’ (אֶחָד), usually translated “one,” is a fascinating word because its precise meaning depends upon its context.
Simple Singularity
Often echad simply refers to a single person, object, or day.
- Genesis 1:5 – “There was evening and there was morning, the first (echad) day.”
- Genesis 2:11 – “The name of the first (echad) river is Pishon.”
These are straightforward examples of numerical singularity.
Compound Unity
In other passages, however, echad describes a unity composed of multiple parts.
- Genesis 2:24 – “…and they shall become one (echad) flesh.” Two persons become one marital union.
- Genesis 11:6 – “Indeed the people are one (echad).” Many individuals are viewed as one people.
- Exodus 26:6 – “…that the tabernacle may be one (echad).” Numerous pieces are joined together to form one tabernacle.
These examples demonstrate that echad can describe either singularity or a unified plurality, depending upon the context.
The Shema
This observation becomes significant when reading the Shema: “Hear, O Israel: The LORD our God, the LORD is one (echad).” (Deuteronomy 6:4)
The Shema unquestionably affirms biblical monotheism. There is only one God. At the same time, the word echad itself does not require an absolutely indivisible singularity. It is entirely compatible with the concept of a unified plurality.
Some have argued that if Moses had intended to emphasize an absolute, solitary oneness, he could have used the Hebrew word yachid (יָחִיד), meaning “only one” or “solitary one,” as in Genesis 22:2: “Take now your son, your only (yachid) son Isaac…”
Whether or not that argument is decisive, the important point remains that the Shema’s use of echad does not itself exclude the fuller revelation of God’s tri-personal nature found in the B’rit Hadashah.
The Christian doctrine of the Trinity is therefore not a denial of the Shema. Rather, Christians understand it to be the fuller revelation of the one God who first declared His oneness to Israel and later revealed Himself more fully as Father, Son, and Holy Spirit.