False Leaders (long article, but worth the read)

A DIFFERENT GOSPEL

Galatians 1:8 "But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed."

Both Mohammed and Joseph Smith had an angel appear to them and show them through strange writings a different gospel. Islam minimizes Jesus to a mere prophet, and Mormonism creates a different Jesus who had two wives and attained godhood in a preexistent state.

2 Corinthians 11:3-4 "But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him."

Should be corrupted is phtheiro in Greek, meaning waste away, shrivel or wither, to spoil (by any process), or to ruin (especially by moral influences, to deprave).

Simplicity is haplotes in Greek, meaning singleness, sincerity, mental honesty; the virtue of one who is free from pretense and hypocrisy; not self-seeking, or openness of heart manifesting itself by bountiful generosity.

Don't let anyone add to or take from your simple faith in Christ. There are different kinds of gifts and services and works which grow from relationship with Jesus. God has blessed His Body with various abilities for healthy wholeness, not to create division (1 Cor. 12). If someone has faith in the Biblical Jesus for forgiveness of their sins, then that person is a brother or sister in Christ. If they trust in some other person or teaching for their salvation, then they are not in Christ.