We don't know what judgment anyone will have. God looks at the heart. He sees accurately and judges mercifully. Jesus is the judge, not us.—Matthew 25:31-40

I think that there is a distinction between what is taught overall and whether the individual members are Christian. We are none of us perfect and all of us have growing to do, including Mormons, Catholics, and Jehovah's Witnesses. Perhaps that growth will lead to individuals changing their affiliation, but to imply that they are not Christian is just not right.