"You must purge the evil from among you." (Deuteronomy 13:5)
Moses warns against three sources of temptation to idolatry. First, the prophet or dreamer who performs signs and wonders and then says: let us follow other gods. Even if the sign comes true, do not listen. The LORD is testing you to know whether you love him with all your heart and soul. The prophet who counsels apostasy must be put to death, however impressive their credentials. Second, the relative or close friend who secretly entices you to serve other gods. Show them no pity; hand them over. Third, the city that has been led away from the LORD; it must be completely destroyed.
The severity of these commands reflects the understanding that apostasy is not a private spiritual matter but a mortal danger to the covenant community as a whole. You must purge the evil from among you. This phrase recurs through Deuteronomy as the refrain of the community's responsibility for its own moral integrity. The Catechism draws from this principle the Church's responsibility for communal moral seriousness: the toleration of grave public scandal injures the whole body (CCC 2287). The love that allows evil to remain unchallenged in a community is not love but abdication.
Brothers and sisters, if a sign is impressive but the message leads away from God, the sign is not from God. The test of a prophet is not the power of the sign but the direction of the counsel. Does it draw you toward the one God or away? Supernatural phenomena that draw toward Christ are to be received with gratitude and discernment. Supernatural phenomena that draw away from him are to be rejected regardless of their impressiveness.
Lord God, give us the discernment to test every spirit by whether it draws us toward you or away. Purge from our communities the evil that corrupts the whole. And let our love for you exceed our love for anyone who would draw us from you. Through Christ our Lord. Amen.