The old Testament gives us several widows who had remarried and were blessed: Boaz and Ruth (Ruth 2:1-13; 4:1-17), David and Abigail (1 Samuel 25:14-42). So, we do have a precedent for widows remarrying with Gods permission. But what does the New Testament tell us about widows remarrying?
The Bible says, "A wife is bound by law as long as her husband lives; but if her husband dies, she is at liberty to be married to whom she wishes, only in the Lord." (1 Corinthians 7:39). If the answer to this question is so clear cut, then why have some said that widows should be content in their current state? Well, it is due to a misunderstanding of 1 Corinthians 7:40, "But she is happier if she remains as she is, according to my judgment—and I think I also have the Spirit of God." So, while Paul, the writer of 1 Corinthians, tends to lobby for widows remaining single, he does so because of his desire for everyone to put their efforts to the ministry. But he still enthusiastically praises the role of marriage.
So, is Paul contradicting himself? No. He is saying that a person should involve the Holy Spirit into the decision, choose wisely, and act appropriately before planning to remarry, because one choice is as good as the other.
More than once I've seen people rush into marriage not long after their spouse died -- often because of loneliness. But frequently they've had a very difficult time adjusting to a new spouse, and in some cases, this has led to separation or divorce. The older we get the harder it is for us to change our ways -- and that can lead to much conflict and disappointment. Remarry only if you are convinced it is God's will and you know it is for love.