When you are in love, you are excited about the relationship and time spent together and want to tell someone. Likewise, when you are in love with Jesus, you can not keep to yourself the joy that comes from knowing Him—it just spills over, bearing witness and strengthening other believers. As you give testimony of who God is and how He works in your life, others will pick up on the deep, genuine gladness in your heart that goes beyond natural happiness. 

People who do not yet know the Lord will find themselves hungering for the joy you have, and they will be drawn to His spirit in you. Witnessing is not a matter of eloquence or talent. It is an overflow of a personal relationship with Jesus Christ. As you allow the Holy Spirit to express His power through you, contagious joy will be the fruit of His indwelling presence. You will be filled with the experience of knowing Jesus and want to invite others to share in that joy. — 1 John 1:1-4