I Cor. 2:1-2 Dear brothers and sisters, when I first came to you I didn't use lofty words and brilliant ideas to tell you God's message. For I decided to concentrate only on Jesus Christ and his death on the cross.
You don't have to be a scholar to be a witness for Christ. In his epistle, John begins with just stating that what he was writing about was Jesus, whom he had known personally. He had walked with Him, talked to Him, shared life with Him. John just shared his own personal encounter with Jesus. The most effective witness is just that, our personal story of how Jesus has touched our lives.
You don't have to use lofty words. Most of the time, people will not listen to you if you do because most people don't talk that way. We must be careful that we don't use "church language" to the point where people who don't go to church have no clue what we are talking about. We need to keep it simple so that understanding can be had.
We don't have to overpower people with what we know. It's not what we know that matters, it's who we know--Jesus. People only need Jesus. They need to know that He loves them, died for them, and can save them. People need to know that there is a solution to their sin problem. People need to know that there is hope, not only for this life, but for all of eternity.
Tell whoever will listen to you, Jesus saves. Tell them what Jesus has done for you and what He can do for them. Tell them often. There is nothing more important to talk about in all the world. People must know about Jesus. If you love the Lord, you will share Him with whomever you can until He comes.