Q #9: Why does my grandmother think living with my girlfriend is wrong?
A: Well, I can't really answer for your grandmother. However, if your grandmother is a Christian, there are a number of basic reasons why Christians object to co-habitation on the plain language of the Bible.
There are literally dozens of passages in the New Testament that forbid sex outside of marriage. See John 8:41; Acts 15:20, 29;21:25; 1 Cor. 5:1; 6:13, 18; 2 Cor. 12:21; Gal. 5:19; Eph. 5:3; Col. 3:5; Rev. 2:21; 9:21. The word translated "sexual immorality" in the New Testament is actually the Greek word "porneia", which refers to all sexual activity outside of marriage (heterosexual or homosexual).
But make no mistake about it! God blesses the sexual union of married people. See the words of Hebrews 13:4a, "Marriage is to be held in honor among all, and the marriage bed is to be undefiled."
Beyond this basic injunction from scripture regarding all sexual behavior outside of marriage, believers in Christ are exhorted to cleanse their lives of "impurity". Consider Ephesians 5:3, "But among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God’s holy people." Or Colossians 3:5, "Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry."
These suggest that the person who is following Christ needs to make putting their sexuality in order a high priority. It's a basic part of being a Christ-follower that leads to blessing for those who will let God's perspective on these things take over. Conversely, it is something that puts our lives on a collision course with God's judgment, if we decide to take our own path with sexuality. The words of 1 Thessalonians 4:3-8 make this point abundantly clear, "It is God’s will that you should be sanctified: that you should avoid sexual immorality; that each of you should learn to control your own body in a way that is holy and honorable, not in passionate lust like the pagans, who do not know God; and that in this matter no one should wrong or take advantage of a brother or sister. The Lord will punish all those who commit such sins, as we told you and warned you before. For God did not call us to be impure, but to live a holy life. Therefore, anyone who rejects this instruction does not reject a human being but God, the very God who gives you his Holy Spirit."
Don't imagine this is simply outdated thinking. The ancient Roman empire, where the New Testament was composed, was a place with plenty of loose attitudes about all kinds of sexual practices. These scriptures do not point to an "old-fashioned" way of thinking of sex or morality, but were written in direct opposition to many of the attitudes and practices in the culture in which they were conceived.
Here are another set of scriptures dealing with sexuality, if I haven't provided enough in this post: (Ex. 20:14; Acts 15:20; Rom. 13:13; 1 Cor. 6:15–18;Gal. 5:19–21; Eph. 5:5–6; Col. 3:5; cf. Gen. 39:7–10; 1 Cor. 5:11; 1 Peter 4:3).
So that's likely why your grandmother thinks your living with your girlfriend is wrong.
I'm personally surprised by how many people I know come to church, claim Christ as their Savior and are sexually active without being married to their lover.
It really doesn't matter what reasoning you might put behind living with someone outside of marriage. If pre-marital sex is involved and you want to live your life as a believer, you must get married or abstain from sex.
Check out more posts from the 31 Questions series on subjects as varied as marijuana, infidelity, 666, the eternal destiny of children who die, dealing with discouragement, cremation, and even speaking in tongues!