"The Shema proves God is one, so no Trinity"
The claim, stated fairly
"Hear, O Israel: the LORD our God, the LORD is one" excludes any plurality in God; Maimonides used yachid, a unique unity.
The Shema says echad, a word used for compound unity, and Messianic Jews say the Shema too.
Echad is used of "one flesh" for husband and wife (Genesis 2:24) and of one cluster of grapes (Numbers 13:23). Maimonides' creed uses yachid; the Shema does not.
Yeshua quoted the Shema as the first commandment (Mark 12:29). The New Covenant teaches one God, known as Father, Son and Spirit, not three gods.
The text
4שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהוָ֥ה אֱלֹהֵ֖ינוּ יְהוָ֥ה ׀ אֶחָֽד׃
4HEAR, O ISRAEL: THE LORD OUR GOD, THE LORD IS ONE.
WEB/WMB: Hear, Israel: The LORD is our God. The LORD is one.
Deuteronomy 6:4 (Hebrew, JPS 1917, WMB)
24עַל־כֵּן֙ יַֽעֲזָב־אִ֔ישׁ אֶת־אָבִ֖יו וְאֶת־אִמּ֑וֹ וְדָבַ֣ק בְּאִשְׁתּ֔וֹ וְהָי֖וּ לְבָשָׂ֥ר אֶחָֽד׃
24Therefore shall a man leave his father and his mother, and shall cleave unto his wife, and they shall be one flesh.
WEB/WMB: Therefore a man will leave his father and his mother, and will join with his wife, and they will be one flesh.
Genesis 2:24 (Hebrew, JPS 1917, WMB)
In the New Covenant
29Yeshua answered, “The greatest is: ‘Hear, Israel, the Lord our God, the Lord is one.
Mark 12:29 (WMB)
Where scholars disagree
Echad can simply mean "one" or "alone", and the Shema alone does not prove a Trinity. Our point is narrower: it does not exclude one.
Sources
- Maimonides, Mishneh Torah, Foundations of the Torah 1:7
- Numbers 13:23
- Hebrew: Westminster Leningrad Codex. English: JPS 1917; World Messianic Bible (public domain).