Who is a brother or sister in Christ? Core doctrines required: the identity and saving work of Jesus — his real existence, death, resurrection, and forgiveness of sins through faith.

The non-negotiable is faith in the identity and work of Christ: real historical existence, sinless life, death on the cross, bodily resurrection, and forgiveness through trust in him alone. Secondary issues (inerrancy debates, gender roles, specific historical details of the Gospels) do not disqualify someone from being a Christian, though they may indicate spiritual immaturity. Outright denial of the resurrection or Jesus's existence disqualifies. Profession without repentance and submission to Christ's lordship is also insufficient (James 2 — even demons believe).