Deuteronomy 13:3 shows God testing Israel through false prophets — same logic as heresies revealing the approved in 1 Cor 11:19.

In Matt 18:7, Jesus says stumbling blocks are inevitable — matching Paul's 'there must be factions' in 11:19, both warn of those who cause them.

1 John 2:19 says false teachers leave to show they were not truly part of us — parallels the purpose of factions revealing the genuine.

In Luke 17:1, Jesus states it is inevitable that stumbling blocks come — same idea as Paul's 'there must be factions' in 11:19, with a warning.

In Acts 15:5, believers from the Pharisee party demand circumcision—a concrete example of the factions within the church that reveal the genuine.

In Acts 20:30, Paul warns of men from within drawing disciples away — similar to the factions in 11:19 that test who is approved.

In 2 Peter 2:1, false teachers secretly bring in destructive heresies—directly echoing the necessity of heresies to test true believers.

Titus 3:10 prescribes rejecting a divisive person after warnings — complementing Paul's point that factions reveal the genuine.

In Galatians 5:20, heresies (same Greek word) are listed among works of the flesh—directly connecting factions to sinful behavior that reveal true believers.

2 Corinthians 13:5-7 urges self-examination to be approved — directly relates to the 'approved' revealed by factions.

Judges 3:4 says nations were left to test Israel — same testing purpose as heresies revealing the approved.

In 2 Corinthians 10:18, approval comes from the Lord, not self-commendation — echoing the theme of genuine recognition through factions in 1 Corinthians 11:19.

2 Corinthians 13:7 expresses desire that you may not do wrong, even if it means failing the test — relates to the testing of genuineness in 1 Corinthians 11:19.

In Acts 28:22, the Roman Jews say the Christian sect is spoken against everywhere—same term 'hairesis' applied to the whole Christian movement.

In 1 Tim 4:1, Paul predicts some will fall away from the faith — the factions in 11:19 may be a test, but here the focus is on deception and apostasy.

In Acts 24:14, Paul confesses worshipping God according to the Way, which opponents call a sect—again using 'hairesis' for the Christian movement.

In Acts 24:5, Paul is called a ringleader of the sect of Nazarenes—using the same Greek word 'hairesis' for heresy, but from outside perspective.

Luke 2:35 says the sword (Christ's rejection) will reveal hearts — similar to heresies revealing the approved.