Regardless of the reasons behind your separation or divorce, no matter what you have done wrong or where you have failed, you can fully restore your relationship with God and be used by Him.
"If you think that being divorced disqualifies you from being used by God, then you have to cancel a million different people today who are being used greatly by God," says Dr. Myles Munroe. "You're saying that divorce is stronger than the blood of Jesus, the forgiveness of God, and the grace of God. That's ridiculous. Divorce is an incident. It's not a lifestyle.
"God forgives. God forgets. What God forgets, you shouldn't try to remember. God will use you no matter what you've done. If I were to ask you the question, 'Is divorce worse than murder?' obviously you would say, 'No way.' If divorce is not worse than murder, then why did God use Moses? Moses was a murderer and a convict."
Also in the Bible, Paul was responsible for the deaths of many people, and God chose him to be one of the greatest preachers ever. God wants to use you for great works that honor Him. Choose to surrender your life to Jesus, and you will be amazed at what you can accomplish through Him.
"Immediately he [Paul] began preaching about Jesus in the synagogues, saying, 'He is indeed the Son of God!' All who heard him were amazed. 'Isn't this the same man who persecuted Jesus' followers with such devastation in Jerusalem?' they asked. . . . [His] preaching became more and more powerful, and the Jews in Damascus couldn't refute his proofs that Jesus was indeed the Messiah" (Acts 9:20-22 NLT).