A third way God “advertises” Himself to the world is through changed lives of His followers.  Of course, believers who choose to live focused upon themselves and earthly concerns are a deterrent to God’s public relations campaign.
But it must be said that Jesus-followers who allow Him to live through them (Galatians 2:20) are strong lighthouses to direct observers to the safe harbor of life with God.

This is what convinced me that God was real and that the Bible was His love letter to me and the true owners’ manual for my life.  I saw my brother’s changed life as he chose to follow Christ, and this motivated me to give my life to God by putting my trust in what Jesus had done by paying my sin penalty.

“Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven.”                            Matthew 5:16

“A new commandment I give to you, that you love one another, even as I have loved you, that you also love one another. By this all men will know that you are My disciples, if you have love for one another.”                                             John 13:34-35

“Keep your behavior excellent among the Gentiles, so that in the thing in which they slander you as evildoers, they may because of your good deeds, as they observe them, glorify God in the day of visitation.”                               1 Peter 2:12

“Now as they observed the confidence of Peter and John and understood that they were uneducated and untrained men, they were amazed, and began to recognize them as having been with Jesus.”                                                                  Acts 4:13

O Lord, let me cling to You in such a way that Your life flows through me.  Let people among whom I live see You in me, and desire to know You because of that.  Let me not mar Your image and repulse people from You.