I am engaged to marry a woman whose husband has abandoned her. Is being deserted grounds to marry again?
Moses allowed divorce because of the hardness of hearts. But Jesus overturned Moses with respect to marriage and divorce by not allowing the putting away (divorcing) of your wife. Jesus went back to the way it was from the beginning and said, "Whosoever putteth away his wife, and marrieth another, committeth adultery: and whosoever marrieth her that is put away from her husband committeth adultery." Luke 16:18. (see also Matthew 19:8-9 and Mark 10:11-12).
The marital escape clause has been closed. By illustration, a dike is designed to hold back water. If a small hole is drilled in the dike, the water will escape and eventually erode the entire dike and render it useless. In order to preserve the dike, the hole must be sealed. So it is with marriage.
If a spouse in a lawful marriage has been abandoned or deserted, the abandoned party to the marriage is to remain unmarried or be reconciled (1 Corinthians 7:11). They are to pray, continue to be longsuffering, and wait patiently in hope. God may use the abandoned party to save the sinner (1 Corinthians 7:16).
God desires that none perish, but that all should come to repentance (2 Peter 3:9). The one who has been abandoned should pray continually that their spouse come to Jesus and be saved. Jesus gave us the parables of the lost coin and the lost sheep to illustrate how much He desires to seek and save the lost. The abandoned spouse, because of their oneness with the lost one, is in an ideal position to be used for the saving of their sinning spouse.
Our focus is to remain on Christ. The act of desertion by one party is not grounds for the abandoned party to also abandon what God has joined together. We do not follow the acts of a sinner to also commit sin.
When a husband is dead, his wife is free to marry another (1 Corinthians 7:39). If the husband puts away (divorces) his wife, or he abandons or deserts her, is he considered "dead" so that she might be free to marry another?
No. Even though he is "spiritually dead," as long as he is physically alive, he has the ability to reconcile with his wife. Once he is "physically dead," then he will no longer be able to reconcile with his wife and she will be free to marry another. The principle is that God desires that no one be lost and should be given a chance to repent during his entire life. The same remedy applies if the wife deserts her husband.
There is at least one proper use of abandonment that is approved by God. We are called to abandon the acts that are offensive to Him.
For more information on divorce and remarriage see Permanency of Marriage.