Christians should not support the weddings of Christian couples who fornicate and believe it is permissible even though the Bible calls fornication sin, John Piper has suggested.
Responding to a question on whether a Christian should attend the wedding of a couple already living together, Piper, founder of desiringGod.org and chancellor of Bethlehem College & Seminary in Minnesota, gave a nuanced response addressing various relationship situations but drew a line in the sand for professing Christians who see fornication as permissible in committed relationships.
"If they are moving away from fornication because they are now persuaded it is sin, and they are marrying as a declaration of repentance and faith in Christ and a commitment to righteousness, then they are right with God. We should join them in the penitent and happy celebration," Piper said.
"But it is possible that they are not at all persuaded that having sex together as an engaged couple is sin. Maybe they would do it all over again in the same way. Many in our day, tragically, are deluded about this because of how superficially they submit to Scripture. They don't submit themselves to God's authority in Scripture. They just do what they feel like doing, and assume God is okay with it — like sleeping together before they're married because they think they're committed to each other," Piper explained before drawing on Scripture.
"It is clear from Scripture that not only is adultery — sexual unfaithfulness in marriage — sin, but sexual relations before marriage is sin as well. That's clear. The very term sexual immorality as it's used in these verses makes it clear: Matthew 15:19; Hebrews 13:4; Ephesians 5:5; 1 Corinthians 5:11; 1 Corinthians 6:9; 7:1–2. All refer to fornication, or sexual relations before marriage," he said.
A Bible-believing Christian couple that believes fornication is permissible should be "disciplined" said Piper.
"If the couple that we're talking about here, whose wedding you're going to attend, has only stopped doing the act of fornication, but has not stopped believing that fornication is right, then they probably (if they belong to a Bible-believing church) are in a position where they should be disciplined — because we don't just discipline people for unrepentant actions of sinning, but also for unrepentant belief that sin is right or permissible," he noted.
"If they are professing Christians getting married, that makes the relationship all the more difficult and complicated since the Bible says we are to disassociate from brothers, professing brothers, who live in this kind of sin (1 Corinthians 5:11). But if they are not professing Christians, there may be numerous ways in which we can extend the grace of God toward them in the hope of conversion," Piper further added.
Piper cited 1 Corinthians 6:9 as evidence that patterns of behavior like fornication destroys the soul, which "is like murder — murder in our heart."
"'Those who do such things will not enter the kingdom of heaven,' Paul says (1 Corinthians 6:9). He's talking about fornication, not just homosexuality. What complicates the question being asked, then, is that if the couple approves of fornication — they don't think it's wrong for an engaged couple to have sex — and they are professing Christians, then the Bible says, 'Now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality . . . not even to eat with such a one' (1 Corinthians 5:11)," he explained.