As Christian parents, you want your child to be converted and share in the salvation that Jesus provides. If your child is a teenager, it might be harder to lead him to Jesus. Teens are going through physical and emotional changes and might have doubts about God or they might approach religion with skepticism. Be patient and pray. As your teen watches and listens to you, God can work in him through the Holy Spirit.
Talk to your teen about God and Jesus. Don't overtly preach and recite Bible verses if they have been disobedient. The best approach is to talk about Jesus in daily conservations. For example, when you are outside with your teen, remark on the beauty of nature and remind him that God was the creator of the world. If a loved one dies, be vocal about Jesus' role as comforter in the midst of sadness.
Share your conversion experience. One's testimony is a powerful tool when leading others to Christ. Tell your teen about your life before you accepted Jesus. If you were a child at the time, then describe what it was like growing up knowing Jesus -- how you went through bad times, but He was always there. If your testimony is one that includes times of rebellion, you might not want to share every detail. This will depend on your child's maturity. The important element is how Jesus changed your life.
Explain the Gospel with simplicity. Teens need to know in straightforward terms about the need for Jesus in their lives. Instead of using preachy phrases, explain the steps involved in accepting the Lord. Begin with acknowledgement of one's sins and awareness that no one can do anything to pay the debt for sin. Then talk about God's love for us, which was demonstrated by sending His son into the world to die for the sins of mankind. The last steps are to believe that Jesus died and was resurrected.
Help your teen understand how to pray for salvation. This prayer doesn't have to be elaborate. Give your child an example of what is commonly called The Sinner's Prayer. You can write it down or print a copy from a Christian site. Ask him whether he would like you to pray with him, but emphasize that he can pray in his heart and still be accepted by Jesus.