After his marriage, David continued to travel and work with his mother in her evangelistic ministry. He had two children by the time he finally stopped touring with his mother to become the pastor of a Christian Missionary Alliance church in Valley Farms, Arizona. He served there from 1949 to 1951. My dad built this, his first church, with his own hands. The building was constructed of old adobe blocks transported from nearby ruins. One of my first childhood memories is of riding atop those blocks in an old flatbed trailer.
Valley Farms was a turning point in my dad's life, because it was there that he began to develop a deep-seated bitterness and hatred toward the established church. This hatred of the church system would later become one of the foundation doctrines of the Children of God. Dad was expelled from the very church he had built himself. There are two conflicting stories.
My father's version is that he was endeavoring to witness to the Indians who populated a nearby reservation: "I would invite the dirty, barefooted Indians to the church service on Sunday and the 'white' members resented it. They were racist hypocrites! So they kicked me out."
Another version concerns a sexual scandal in which he was allegedly involved. Until recently, I discounted rumors of this as hearsay. However, a cousin has told me that my dad sent a tape recording to his parents in California at the time of his dismissal. In the tape he categorically denied the charge of sexual misconduct and bitterly defended his position, calling the accusation a lie.
Who knows the truth, except my father? My dad was always trying to be radical in his Christianity; this would explain why he would bring "dirty, barefooted Indians" into his church to which a white, prejudiced congregation would take offense. On the other hand, knowing my dad's sexual weakness, I believe there could certainly have been a scandal. Whatever the case, the event gave birth to a bitterness that grew into a deviant, consuming hatred of the established church.

Source:
The Children of God: The Inside Story - Chapter 2 - The Inheritance