Why Is God Called "Heis" and Not "Monos" in Jesus' Quotation of the Shema?

In Mark 12:29, Jesus uses εἷς ("heis") because He is quoting the Shema in the form known from the Greek translation of the Old Testament. This word proclaims that the Lord is one, the only God of Israel; however, the distinction between εἷς and μόνος alone is not an independent "proof" of a compound unity or the doctrine of the Trinity.

The Shema and the Text Jesus Quoted

The Shema is the central confession of faith of Israel, beginning with the words "Hear, O Israel." In the Hebrew text of Deuteronomy 6:4, the word is echad (אֶחָד), the common numeral "one." In the Greek Septuagint, which was widely used by diaspora Jews and the early church, this word is rendered as heis (εἷς). It is this very biblical form that Mark reproduces.

“Hear, O Israel: The Lord our God, the Lord is one!” Deut 6:4

“Jesus answered him, ‘The first of all the commandments is: “Hear, O Israel, the Lord our God, the Lord is one.”’ ” Mark 12:29

Thus, the reason is primarily textual rather than a hidden theological play on words: the Greek translation of the Shema traditionally had εἷς, and Christ affirms this foundational biblical confession.

What εἷς and μόνος Mean

The word εἷς means "one" as a numeral: one God, one person, one day, one body. It corresponds to the Hebrew echad in many ordinary contexts. In the Shema, its primary emphasis is this: Israel must not divide its allegiance between the Lord and pagan deities. The Lord is not one among many; He is the one true God of His people.

Μόνος usually means "alone," "only," or "sole" in the sense of exclusivity: for instance, when someone is by themselves, or when a right, glory, or power belongs solely to one entity. It is not an identical word to the numeral εἷς, so substituting it would alter the familiar form of the Old Testament quotation and its immediate syntax.

At the same time, we should not jump to the unwarranted conclusion that μόνος necessarily implies "lonely" or that it negates God's love and fellowship. The New Testament can apply this word to God to proclaim His exclusive sovereignty and glory.

“To God our Savior, Who alone is wise, be glory and majesty, dominion and power, both now and forever. Amen.” Jude 1:25

Here, "alone" conveys the idea of God’s exclusivity, not an assertion that God cannot have an inner personal life. Likewise, εἷς in Mark 12:29 directly affirms God's oneness, but on its own does not explain every aspect of God's nature.

Does "Echad" Prove a Compound Unity?

It is sometimes pointed out that echad is used of the unity of multiple persons. This is true: a husband and wife, while remaining distinct persons, become "one flesh."

“Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh.” Gen 2:24

However, echad also frequently means simply "one." Therefore, it is unfair to build the doctrine of the Trinity solely on this single word from the Shema. The word does not deny the multifaceted nature of God's being, but neither does it fully formulate it. Sound theology listens to the entire biblical canon rather than placing upon a single grammatical detail a weight it cannot bear by itself.

The One God in the New Testament Witness

The apostles maintain strict biblical monotheism: God is one. Yet at the same time, they speak of the Father, the Son, and the Holy Spirit in the context of salvation, worship, and divine activity. Paul proclaims one God, the Father, and one Lord, Jesus Christ; these are not two competing gods, but the Christian confession of the one God revealed through the Father and the Son.

“Yet for us there is one God, the Father, of whom are all things, and we for Him; and one Lord Jesus Christ, through whom are all things, and through whom we live.” 1 Cor 8:6

Jesus also gave the baptismal commission using the singular "name," uniting the Father, the Son, and the Holy Spirit. This is an important biblical witness to the unity of the Godhead and the genuine distinction of the Persons.

“Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.” Matt 28:19

Seventh-day Adventists profess one God: Father, Son, and Holy Spirit, a unity of three co-eternal Persons. Ellen White wrote of the "three living persons of the heavenly trio," emphasizing not three gods, but the fullness of God's presence and action in salvation.

Conclusion and Practical Application

Jesus said εἷς, not μόνος, because He was quoting the Shema according to the Greek biblical tradition: "The Lord is one." εἷς is the exact equivalent of the biblical "one" in this quotation; μόνος would have conveyed a different nuance: "only," "alone." We should not pit these words against each other as if one automatically proves the Trinity and the other dismantles it. The divinity of Christ, the personality of the Holy Spirit, and the unity of the Godhead are revealed through the cumulative witness of Scripture.

Practically speaking, the Shema calls us to undivided loyalty: to leave no room in our hearts for modern idols—such as control, wealth, success, or self. Let us daily confess: the Lord is one, and therefore He is worthy of all our love, trust, and obedience.