1 corinthians 7: what is your concern?

 While some members had immoral sexual relations, others, went to another idea: don't have sex even with his spouse. They asked Paul about it. Paul answered in a balanced way: sex in marriage is to please the spouse. Although "no sex" seems much more spiritual, in fact, one's body is not his own; it belongs to the spouse. Paul recommend that in a marriage with a non believer, the Christian must remain the marriage, so that the Christians blesses the non believer.
 The Christian must be guided by love and not by self interest. Sometimes, a great ascetic decision as "no sex" must seem beautiful, but it may be a disguised selfish decision. The Christian must not be concerned about himself but be concerned to praise the Lord.