Revelation 3:20

Behold, I stand at the door and knock.  If anyone hears My voice and opens the door, I will come to him and dine with him, and he with Me.

We became a born-again believer because we recognized Jesus knocking at the door.  God probably sent people across our path to speak into our lives to help lead us to Him.  As Christians, remember that our experiences before we got saved are the best witness to the unsaved.  Who better to show the love of Christ to the unloved than someone who has received the forgiveness themselves.