We would first like to commend you for your respect for God’s laws. Although there are no scriptural references that specifically forbid unmarried couples from living in the same abode, it certainly makes good moral sense to live apart. Here's why. In speaking to unmarried widows, the Apostle Paul in 1 Corinthians 7:9 says, “For if they are not practicing self-control, they should marry. For it is better to marry than to be aflame with passion.” In this passage the Apostle places “practicing self-control
opposite being “aflame with passion.” Paul is clearly saying that it is better to marry than to be tempted by the passion, which goes against self- control. When a couple is living in the same house, even though they are
not sexually intimate, they are playing with fire. Jesus tells us to pray that we be delivered from temptation (Matthew 6:13). This is pretty hard to do when you are living with temptation. Considering how often sexual sin is condemned throughout the entire Bible, thinking that you would be strong enough to live together without sin ignores the obvious pull of sexual temptation.
But even if you are both strong enough to still live together and not be sexually intimate, your example sends a message to others who are not as strong as you that it is acceptable to live together. Paul is clear in his argument about eating idol-meat (1 Corinthians 10:31-33; 11:1) that if you do something which you do not consider sin, but in so doing you cause other Christians to follow, and they do sin, then you will have to answer to that.
In arguing that you can live together and not sin, you ignore how hard it is for people, especially in our culture, to live sexually pure lives, even when married. If you, as a Christian, argue that it is permissible to live with your fiancée outside of the marriage bond because you are strong enough not to sin, and some other Christian is led astray by your actions, you will be called into accountability. Paul teaches throughout his writings that we are not our own—we no longer have our own “rights” but we are tied to Christ. All our actions should be measured by the glory they bring to God. You must ask yourself, “Are my actions glorifying God's laws? Am I a good Christian example to others of one following in our Lord Jesus' footsteps?” If the answer to either of these questions is negative, then we would advise you to live separately until you marry in July.