Have you ever had a Jehovah's Witness knock on your door? How about a Mormon? perhaps you have talked to someone who is in to christian science or spiritism. The fact is that today throughout the world there are millions of cultists over 17 million cult members are in the United States alone.
If there was a way to show them Christ's love don't you think as christians we owe them salvation? In order to help them we need to understand them. And in order to understand them we need to carefully learn their theological views and terminology. In Walter Martins book "Kingdom Of The Cults" He calls it "Scaling The Language Barrier"
Just Imagine if every christian home welcomed every cultist that knocked on their door in for a bible study with full understanding of what that cultist is about to say. We have a wonderful ministry in our own homes that christ wants us to take advantage of.