Testimony

Mark 5:19 ESV
[Jesus] said to him, "Go home to your friends and tell them how much the Lord has done for you, and how he has had mercy on you."

I think we usually underestimate the power of a simple testimony of our experience with the Lord.  A spiritual conversation can get derailed by complex logical/philosophical arguments (which do have value in certain conversations), so I think it is important to take the opportunity to simply provide first-hand account of how the Lord has saved us, changed us, and walked with us.

Revelation 12:10-11 ESV
And I heard a loud voice in heaven, saying, "Now the salvation and the power and the kingdom of our God and the authority of his Christ have come, for the accuser of our brothers has been thrown down, who accuses them day and night before our God. And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death.

Heavenly Father, thank you for saving me and rescuing me from destruction.  Thank you for loving me and giving me a life and a future.  Thank you for the opportunity to be an ambassador for Christ and announce the good news of His reign.  Lord, please help me be a faithful witness - to share how you have loved me and restored me to sonship.  I love you, and I pray in the name of Jesus Christ.