Acts 4:13

Now when they saw the boldness of Peter and John, and perceived that they were unlearned and ignorant men, they marvelled; and they took knowledge of them, that they had been with Jesus. Acts 4:13 KJV

You don't need to be the smartest man on the planet to tell someone about Jesus. You don't need a PHD. to tell some one how Christ saved you. All you need to do is tell them how good he is. Show them from the bible all he has and what he will do. Show them the change in you and a watch them be marvelled by what God can do.