I've known people who join false religions, yet seem sincere in their quest to seek God. If people unknowingly believe a lie, are they still condemned to hear, "I never knew you" (Matt. 7:23)?
It is true that many who join a cult or false religion do so with a sincere desire to please God as He has been presented to them by other members of that religious organization. However, sincerity does not equal innocence before God. Each person comes into the world sinful, fully rejecting God spiritually. As Romans 5:12 says, “Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned.”
It is important to determine what any belief system teaches about the deity of Christ. The Scripture is clear concerning the Word (Jesus) becoming flesh, and that Jesus is the true God and the only way to eternal life (see John 1:1–18; 1 John 5:20). The New Testament reveals that Jesus is equal with God the Father in all attributes of deity, and thus the substance of deity: “[Jesus], being in very nature God, did not consider equality with God something to be used to his own advantage” (Phil. 2:6), and “For God was pleased to have all his fullness dwell in [Jesus]” (Col. 1:19). Our confession of Jesus as Lord includes acknowledgment of His deity: Only God can save us from sin.
Believing the lies of a false religion is not what condemns a person. Only a failure to place faith in Christ—God the Son—dooms one to perish. Therefore, we pray for the Lord to reveal the truth of Christ, in mercy, to all people.