So let me get this right about Trinity?

Close. In the beginning was the Word, and the Word was one with G-d and was G-d. The Word was made flesh and saved us through His sacrifice. The Word called down the Holy Spirit (G-d's force on Earth, bestowing Grace). As St. Patrick is said to have explained the pagan Irish, who understood: The trinity is akin to the Shamrock, three leaves of one plant that would not be the same as the plant would not be without all three leaves, yet is one living person.