One God and One Lord – 1 Corinthians 8:6
The Shema affirms that for Israel there was only one God. Paul reworded it to express that there is one God and one Lord. Not two, but one.
Trinity
The Nature of God: What Is God Like?
What is the nature of God? This post is a quick look at the attributes of God, the Trinity, his will, and some commonly raised questions.
The Trinity: Three Persons With One Essence
The Trinity is a uniquely Christian doctrine, teaching that there is only one God, but in three persons having one essence.