Pastor and author John Piper has said, ‘Those who choose to marry non-believers are acting in open defiance of the teaching of the apostles and of God’. Piper is known for strict Calvinist theology. He said not marrying a Christian indicates how deeply compromised the believer’s love for Christ is; Christians who marry non-believers and ignore their pastors’ warnings ‘should be excommunicated from their church community’. Opposers to excommunication might say, ‘You won’t be able to win them to Christ by putting them out of the church’. But elders must be prepared to hear criticism before declaring this is ‘emphatically not what the Bible teaches’. Not everyone agreed with Piper. Twitter comments included ‘quite literally one of the worst things I have ever read’ and ‘I benefited from Piper’s teaching in the past, but this HAS to be the worst’.