The following devotional is from Greg Laurie:
One of the most effective tools you have in your evangelistic toolbox is telling your story, your personal testimony about how you came to believe in Jesus.
After a conversation with Jesus at the well, the Samaritan woman—minutes old in the faith—immediately went out and told others. The Bible tells us that "many Samaritans from the village believed in Jesus because the woman had said, 'He told me everything I ever did!' " (John 4:39).
It is the power of a changed life. Use your story, because it is a way to preach to a person without preaching at a person. People don't like to be preached to. Your story is a bridge. You can say, "Let me tell you my story. I didn't always believe these things. Here is what I used to be. Here is the way I used to live. Here is what I used to think. But here is what I heard,and this is how it changed my life." They can argue with a sermon, but they can't argue with your story. They can't argue with what God has done for you. So use that story to build the bridge.
Telling your story is a powerful bridge for the gospel message. It is merely a bridge to tell His story. It is not about you; it is about Him. So when you tell your story, don't glorify or exaggerate your past. Sometimes I have heard people give their testimonies, and the story gets more dramatic with the telling. Sometimes Christians want to make their story more dramatic to be more impressive. Just tell the truth.
Don't boast about what you gave up for God, but about what God gave up for you. We gave up guilt. We gave up judgment. We gave up hell. And in their place, God gave us purpose and meaning and heaven. And remember, it is not about you. It is about Him.
As a teenager, I would hang around a place in Newport Beach called the Balboa Fun Zone. I would lean up against a wall, hair hanging in my eyes (use your imagination there), looking real tough. Christians who walked around and handed out their tracts didn't know what to make of me. They would thrust a pamphlet in my direction and then back off. But in my heart I was saying, "Talk to me. Don't be put off by my tough-guy façade. It is false. I am too proud to say that I need help. I am too proud to say, 'Tell me about Jesus.' "
I wanted someone to engage me. I would take the little tracts the Christians gave me and stuff them in my pocket, but never in the trash. I took everything that everyone gave me, everywhere. I had a drawer for all kinds of religious literature at home, and every now and then, I would pull it out, empty it on my bed, and try to sort through it. I had literature from Christians, Mormons, Jehovah's Witnesses, Hare Krishnas, and more. You name it, I had it. I would look at this stuff and wonder what it all meant. I was looking for someone to show me the way.
Most Christians who have a basic knowledge of the faith could have easily explained the gospel to someone like me. And there is a world full of people out there who are just like I was, waiting for someone to take a risk. They are waiting for someone like you to say, "I will go ahead and give it a go." The worst-case scenario is they will say no. But what if they say yes? How willing are you to step out in faith and be used of Him?
Greg Laurie