Question: What does it mean to “test the spirits” according to 1 John:4:1-3?
Response: The usual interpretation has a would-be exorcist demanding of an evil spirit (apparently in possession of a victim) whether Christ has come in the flesh. However, this scripture has nothing to do with exorcism or conversing with evil spirits, but with identifying false prophets and their false teaching. Already in John’s day there were “many false prophets,” and John is declaring that false prophets are inspired by deceiving spirits. In 1 Kings:22:22, such a spirit is given permission by God to be “a lying spirit in the mouths” of Israel’s prophets: one spirit speaks falsely through four hundred prophets to deceive King Ahab (“there was none like unto Ahab, which did sell himself to work wickedness” - 21:25) in order to bring about his death in fulfillment of the true prophecy by Elijah.
At issue is an important doctrine: that Jesus Christ has come once and for all in the flesh, fulfilling His mission in one life on earth, one sacrifice on the cross, and one resurrection. This refutes two related false teachings: reincarnation and transubstantiation. The body of flesh which Christ took (“a body hast thou prepared me” - Heb:10:5) was transformed by resurrection power, not exchanged for another through reincarnation. He came in the flesh once for all time when He was born as a babe in Bethlehem; He does not come again and again in the flesh as priests transmute bread into His body. A lying spirit authored both of these deceitful doctrines, which are among the “doctrines of devils” (1 Tm 4:1) popular today.