The Deity of Christ
The doctrine of Christ is certainly confusing, but it is no less important. Without acknowledging the deity of Christ, one cannot be a Christian. In fact, this is one of the distinctions between Jehovah's Witnesses and orthodox Christianity---the proposition that Christ is God.
That's why I was disturbed this Sunday to hear one of my young Sunday School students assert that Christ was "created" by the Father. He didn't state it as dogmatic fact, but rather he was attempting to answer a question I posed about John 1:1 - 3. I was asking the boys why John was telling us these things about Christ, and the student's answer was something to the effect of, "to let us know that after God created Jesus, Jesus created everything else." Obviously, I corrected him in love, knowing that he had no idea what he was talking about. However, I was also disheartened because he's been in church all of his life where people ostensibly are worshipping someone they claim to be, well, God. This subtle point seems to have escaped my young protege.
It has dawned on me that we have no idea what is in the heads of our children because we have no idea what's being put in their heads. As for me, I will be making a concerted effort with my co-teacher to properly teach our class the truths of Christ and the importance of same.