In short
God the Father
God the eternal Father is Creator, Source, Sustainer and Sovereign of all creation. He is just and holy, merciful and gracious, slow to anger and full of steadfast love and faithfulness.
Read it in the Bible
Genesis 1:1; Revelation 4:11; John 3:16; 1 John 4:8; Exodus 34:6, 7
This is a short summary. The church's full statements are at adventist.org, and our pastors are glad to study any belief with you.