Taken from here
As a believer, you know the condition of those who are outside of Jesus Christ. You understand that they are separated from God, under His wrath, and facing an eternity of misery and damnation. You realize that lost people have no true hope or peace. You are fully aware of their bondage to sin. This understanding burdens you for those who are lost.
Yet, this burden increases when the lost person is someone you know intimately and love. It may be a husband, wife, son, daughter, or other family member. It grieves your heart to know that your loved one is separated from God, under His wrath, and headed for an eternity in hell. You long for your loved one to experience true hope and peace through the Lord Jesus Christ. You yearn for your loved one to be set free from bondage to sin.
What do you do when someone you love is lost? The following are some biblical principles that you can put into practice to help you with this burdensome load:
Realize that there is hope (Acts 16:15, 29-34). In these texts, God saved whole households. His power can reach and change any sinner. Rest in His power and grace that can save your loved one. There are no hopeless cases this side of the grave.
Ask God to grant you patience and persistence (Luke 18:1). Pray that God will grant you the patience to be faithful to this person. When a person turns to Christ in faith, it is usually a process. Ask God to help you to pray, love, and witness to this person for the long haul. Also, pray for a spirit of persistence. Sometimes your loved one may outright reject the gospel. He or she may show no interest whatsoever. Ask God to help you persist in loving, praying for, and ministering to him or her regardless of his or her reaction.
Pray for the influence of other Christians (1 Corinthians 3:5-8). There are times when family members may not listen to you and your witness. Yet, there may be others that your loved one will listen to. Pray that God would send into your loved one’s life believers that he or she will love, respect, and listen to. Plead that He would grant your loved one friends who will be faithful to minister to him or her.
Plead that your loved one will be radically transformed by Jesus Christ (John 3:16). Call on God to change your loved one through His grace and power. There is a tendency to pray for God to change certain sinful habits in a lost person’s life. Yet, a person can exchange sins without experiencing a change of heart. Plead with God to regenerate your loved one. Ask Him to transform your loved one through the power of the Spirit and the gospel.
Ask God for opportunities to demonstrate love to your lost loved one (Matthew 5:13-14). Even when your loved one will not listen to your words, he or she can see your actions. Pray for opportunities to demonstrate the love of Jesus to this person. Ask that they will sense and know the difference in your life because of Jesus Christ.
Pray tenaciously (Isaiah 62:2-7). Wrestle with God concerning your loved. Plead His promises. Claim His Word. Pray for mercy and grace upon your loved one. Determine in your heart to seek God until He answers.
Don’t lose heart (Galatians 6:9). When someone you love is lost, it can be a long, weary struggle. It would be easy to give up hope and feel that he or she will never come to Christ. Yet, don’t give up. Don’t lose heart. God is a merciful and sovereign God. As long as your loved one is alive, there is hope. As long as he or she has breath in the body, there is the possibility of him or her coming to Jesus Christ. In God’s time, you will reap the harvest.