What do Mormon believe about the Trinity ? And what do Jehovah Witnesses believe about the Trinity ? I think they believe the some thing>
They do not believe the same thing.
Mormons believe that the Father is the God of this World. That He once was a human on another planet, but attained Godhood through His life there. That Jesus and Satan are his first offspring with His multiple wives, the rest of his offspring - which by the way are first “Spirit Children” aka Angels/Demons and then at a point in time are born on Earth - everyone’s parents, spouses, children, friends are actualy their siblings. Jesus was born through sexual relations of the Father with his daughter, Mary. Jesus through his life here on Earth and his marriage to Mary & Martha has attained Godhood over another planet. The Holy Spirit is a 3rd God.
Jehovah’s Witness’ believe that the Father is God. That Jesus is His Son and is not God. That the Holy Spirit is not a Person, but is the “action” of the Father.