The best advertisement is a satisfied customer. We all realize that. When we are looking to make a large purchase we frequently ask others what their experience has been. Their testimony is a major factor in helping us decide about who to buy from.
While certainly salvation is not a purchase we make, the principle still holds true. When we are joyful and enthused about Jesus, that is attractive to others and gives them good reason to consider the Gospel.
The greatest thing that we can do as believers is to truly worship the Lord Jesus. When we do that we honor him and we become the best testimonies of his grace. Consider who he is:
He is the image of the invisible God, the firstborn over all creation. For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him. (Col. 1:15-16)
The Son is the radiance of God’s glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven. (Heb. 1:3)
“I am the Alpha and the Omega,” says the Lord God, “who is, and who was, and who is to come, the Almighty.” (Rev. 1:8)
Consider what he did:
Who, being in very nature God, did not consider equality with God something to be grasped, but made himself nothing, taking the very nature of a servant, being made in human likeness. And being found in appearance as a man, he humbled himself and became obedient to death—even death on a cross! (Phil. 2:6-8)
Consider where he is today:
Christ Jesus, who died—more than that, who was raised to life—is at the right hand of God and is also interceding for us. (Rom. 8:34b)
Meditate on the glories of God the Son. Rejoice in his person. Stand in awe of his being. Wonder at his love. Tell him how much you love him.
As you worship Christ constantly and consistently you will be the best testimony that the world can see. As Paul told Titus, you will “adorn the Gospel. . “ (Titus 2:10)