On the one hand, there are people who is in favor of living together before marriage. One of the main reasons why most couples decide on cohabitation is that by living together before marriage, they will know how compatible they are. Presumably, if a couple can get along living together before marriage, they will be able to get along with each other after marriage. Another reason for cohabitation is that the couple don't want to go though the legal processes in case their marriage ends in a divorce. And a last but not least reason is money; a divorce might have devastating economic consequences in one or both parties, while it might not if you are not legally married.