Must be (dei einai). Since moral conditions are so bad among you (cf. chapters 1 to 6). Cf. Matthew 18:7 . Heresies (airesei). The schisms naturally become factions or parties. Cf. strifes (eride) in Matthew 1:11 . See on "Ac 15:5" for airesei, a choosing, taking sides, holding views of one party, heresy (our word). "Heresy is theoretical schism, schism practical heresy." Cf. Titus 3:10 ; 2 Peter 2:1 . In Paul only here and Galatians 5:20 . That (ina). God's purpose in these factions makes the proved ones (oi dokimoi) become manifest (paneroi). "These airesei are a magnet attracting unsound and unsettled minds" (Findlay). It has always been so. Instance so-called Christian Science, Russellism, New Thought, etc., today.