“God said, ‘Let US make man in OUR own image" - Genesis 1
God, here, is revealing himself, as we learn later through Christ in the New Testament:
(1) The love between God the Father + God the Son = The Holy Spirit
(2) The love between a father + a mother = their child/children
God = 1 GOD, but three distinct persons make up GOD; all three of them are UNIQUE, though they are cosubstantial. This is what is meant when we say "God is love."