The essence of salvation by the righteousness obtained by faith. Look at the evidence of conversion, there is confession with the mouth, and this confession finds it source in the heart - that God raised Him from the dead - He conquered death - in His perfection. In the "heart"(inner most being") of a man he believes - stakes his soul on it. We should be excited and eager for the opportunity to explain the good news to others. We want to be used of God as tools to bring people to the knowledge of Christ. We do not need to be ashamed of it and can(and should) give it out as clearly and unadulterated as possible, as the unadulterated Gospel is the power of God to salvation, and the Holy Spirit makes them believe, not us. We find comfort and encouragement in this.