What does 1 Corinthians 7:39 mean?
Paul wraps up this long section about whether unmarried people should get married by addressing one more group: widows. He emphasizes once more that those who are already married should stay married. A wife is bound to her husband so long as he or she lives. In almost all cases, only death should end a Christian marriage.However, if the woman's husband dies, the widow is free to marry whomever she chooses. Paul offers one stipulation by saying "only in the Lord." In other words, a Christian widow should not marry an unbeliever (2 Corinthians 6:14).
In the culture of Paul's day, the widow was in a very different position from young women considering her first marriage. Widows were no longer necessarily under the authority of their fathers and were free to choose their own husband, given the opportunity. At the same time, such widows were especially vulnerable to being exploited or abandoned. Young women generally relied on their fathers to find them a desirable husband. That's why Paul's instructions to widows differ from his earlier instructions to those who are "betrothed."
First Corinthians 7:25–40 explores Paul's response to a question about those who are engaged to be married. Should they go through with it, considering his teaching that singleness provides opportunity to serve Christ undivided? Both are permitted, Paul insists, and you do well in either case. Paul's unique, personal view is that unmarried Christians can serve without the troubles that come with even the best marriages; they can remain fully focused on living for Christ. That is neither a command nor a judgment binding on anyone.
Paul rejects an idea concerning the Corinthian believers: that married Christians should not have sex. Perhaps some even thought marriages should be dissolved and avoided. On the contrary, Scripture says married Christians should have regular sex in order to avoid temptation. Those who are married ought to remain married. Unmarried believers with the gift of celibacy, however, should consider remaining single in order to avoid the troubles of marriage. That is Paul's personal preference, though that gift is not given to all others. Single believers can devote themselves to serving Christ without distraction. The time is short. All believers should live and serve Christ now as if this world is passing away.