The verse reads, “But if the unbeliever departs, let him depart; a brother or a sister is not under bondage in such cases. But God has called us to peace.” This verse is often referred to in an effort to avoid the teaching of Jesus in Matthew 19:9 & 5:32 which gives only one exception for a divorcee and remarriage – formication. First Corinthians 7:15 does not allow another cause for divorce. The subject of divorce is nowhere discussed in the entire chapter! The context reveals the subject to be an unbelieving spouse who is not content to live with their believing mate. There’s nothing said about the believer divorcing and marrying again! Verse 11 says if a couple separates, they are to remain unmarried or be reconciled! The same would apply in verse 15.
The word “bondage” in verse 15 (dedoulwtai from doulow and doulow) is not the word used for marriage bond. The word is found in the Greek New Testament 133 times and never does it apply to marriage. The word means: “slavery, the lowest term in the scale of servitude.” Had the Holy Spirit intended to use the word for the marriage bond, he most certainly could have, as he did in verse 27 (dedesai from dew). A significant distinction is made between the two words.
The point of verse 15 is this: the believer is not so bound (in servitude) to the unbeliever that they must give up Christ to hold to the unbeliever. Nothing must ever come between Christ and one’s faithfulness to him (Luke 14:26), not even a mate. As sad as it is for one to be deserted by their marriage companion, being faithful to the Lord is more important, and as verse 11 says “let her (or him, meh) remain unmarried.”
Another reason it does not and cannot mean the marriage bond is the “tense” of the word in Greek (perfect passive indicative). The use of this tense says, “you are not now bound, nor have you ever been bound.” If this applies to marriage, it would be saying, you are not now bound in marriage, nor have you ever been bound in marriage. That cannot be true because God ordained marriage and what God has joined together, let no man put asunder (Matthew 19:6). However, since the “bondage” here is speaking of a bondage of servitude (or slavery), the tense fits perfectly. You are not so bound in servitude to your spouse that you must forsake Christ to keep your marriage together, nor have you ever been in such a bondage of servitude to leave Christ to keep your marriage intact!