For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
It depends on why she got divorced both times
The situation is about a man not a woman. He got married to a woman who had been married and divorced, that is to say he was her second husband. After a few years of marriage, they got divorced. Now he has given his life to Christ and needs to restitute. How does he go about it? Can he possibly remarry?
All sin requires restitution- whereas, all sins committed both prior to and after salvation are covered by the blood of our Lord Jesus Christ, Romans 3:25
Whenever True Believers sin; we are vexed on every side- it is impossible to get right with Him, until we turn to our Lord and humbly submit ourselves before him in prayer and meditation- crying out and seeking and waiting for his forgiveness- and as always, He withholds nothing from his chosen, Psalms 51
We must always worship our Lord God in prayer… Jesus is Lord of all- when we let Jesus be Lord, all is turned over to Him, Galatians 3:22-24
Once sin is acknowledged, complete forgiveness requires repentance; we are to turn away from everything that is evil and resentful to The Father- therefore, the truly Saved will always attempt to walk humbly before Him.
Should a True Believer become divorced, he or she should consider remarriage only if the life's partner is deceased- otherwise, one should remain physically single and spiritually married to the Lord, Romans 7:2-3, Luke 16:18, 1Corinthians 7:10-16, 39.
I pray that the Grace of our Lord Jesus Christ be with you all.