My friend teaches that if a person is wrong and unteachable about ancillary Bible subjects, such as Spiritual gifts, the dispensations, the sin nature, etc, that the person is filled with lies and the spirit is not with them.
Is there any truth to his statement? “A person who teaches incorrectly about spiritual things can not be saved, because the spirit cannot be with them.”
What you seem to be saying is that your friend believes anyone whose interpretation differs from his on these matters is not saved. This is obviously an untrue statement.
Ephesians 1:13-14 and other places tell us the Holy Spirit was sealed within when we heard the Gospel and believed it, not because of any doctrinal position we held.
Right or wrong, our opinions about ancillary Biblical subjects can not cause the removal of the Holy Spirit whom God has sealed within us unto the day of redemption (Ephes. 4:30).