This sounds like such a silly and unnecessary question for any believer to ask. We know that Jesus commanded in Matthew 28:19-20 (KJV), "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen."
But for some newborn Christians, they were never mentored. Like motherless lambs, they search for sustenance wherever they can find it. Cults seek after such easy prey. These naive followers of Christ are told that they can find deeper knowledge, secrets, power, and other enticing things at their particular gathering place. Little do they know that they're in a cult and getting out of it will take courage and determination.
I was one such stray lamb. When I gave my life to Christ in 1969, the vacation Bible School teacher dismissed us without giving each of us a Bible. Neither did she personally encourage us to go to church but just assumed we'd know where to go. Consequently, I turned to radio preachers for spiritual sustenance.
One of those men was Garner Ted Armstrong. His World Tomorrow program sounded so much more advanced than what I heard from the other preachers. I knew about salvation but only he gave me what I thought was discipleship.
While boarding with a family, I was introduced to a cultic house church. The doctrines taught by their charismatic leader were the same sort which I had heard from Mr. Armstrong. Additionally, he taught heretical lies such as God not being omnipotent, omniscient, and omnipresent. He even claimed that we were once space aliens and that we were born here so we could get uncontaminated bodies to live in. Revelation 12:7, according to him, was an ancient nuclear war.
I wrote about how the Lord eventually rescued me from their baleful influence in a book called How I Was Razed. Read more about this awesome testimony at Amazon.