Christians call God "God" in a personal sense, the Eternal Personage. That God is Absolute and Infinite describe His Perfections.
Yes. Yet, therein lies a trap.
No ....no trap here.
When we consider a word pointing to a personage or thing or concept, we are essentially, creating an idol and the Infinite in His commandments asks us not to do this.
By a Personal God, Christians mean a Divine Being who has an identity that is all His own, the "I AM, WHO AM" (so there is no way of "creating an idol" when understanding The sacred name of God appears in various ways, Exodus 3:14, says, "I AM, WHO AM" that is, I am Being Itself, Eternal, Self-Existent, Infinite, without beginning, end or change, and the source of all other beings.
Sh'ma is our understanding of the Unity or Oneness of God. These classes have been a struggle for me. I am one who comes to God without an understanding of God. I hesitate to name God "God"
Perhaps you could try putting it all together this way...
As you say, Jews understand the unity and Oneness of God through Sh'ma. Catholics confess God's Oneness through the Creed..."I believe in One God" which has its root in the divine revelation of the Old Covenant, Deut. 6:4-5. To Israel, God's chosen, He revealed Himself as the only ONe: "Hear, O Isreal: The Lord our God is one Lord: and you shall love the LOrd your God with all your heart, and with all your soul and with all your might."
Through the prophets, God calls Isreal and all nations to turn to Him, the One and only God. Isaias 45:22-24.
God revealed Himself to His people Israel by making His name known to them. A name expresses a person's essence and identity and the meaning of this person's life. God has a name: He is not an anonymous force. To disclose one's name is to make oneself known to others.
God revealed Himself progressively and under different names to His people, but the revelation that proved to be the fundamental one for both the Old and the New Covenants was th erevelation of the divine name to Moses in the theophany of the burning bush, on the threshold of the Exodus and of the COvenant of Sinai.
God called Moses from the midst of the burning bush..."I am the God of your Father, the God of Abraham, ..of Isaac...of Jacob." God is the God of the fathers, the One who had called and guided the patriarchs in their wanderings, He is faithful and compassionate and remembers them and His promises...He comes to free their descendents from slavery. He is the God who from beyond space and time can do this and will to do it, the GOd who will put His almighty power to work for this plan.
In revealing His mysterious name, YHWH ("I AM HE WHO IS", "I AM WHO AM"or "I AM WHO I AM", God says who He is and by what name He is to be called. He is the God who makes Himself close to us. This is why Christians call God "God" in a personal sense, the Eternal Personage.
No trap, no idolatry. Good, clear, consistent understanding of what God said of Himself.