From the beginning God has spoken to people, wanting us to know him just as he already knows us. He has spoken to us in many ways - through nature, through what's written in the Bible, and finally, through Jesus Christ, his son.
It's through Jesus that we can have a relationship with God. Once we are in a relationship with him, we have the joy of getting to know him better; as we do (and as he works in our lives), we begin to show his life and love to others around us.
God created us and wants to be in relationship with us.
Psalm 139 - You have searched me, Lord, and you know me. You know when I sit and when I rise; you receive my thoughts from afar. You discern my going out and my lying down; you are familiar with all my ways...For you created my inmost being; you knit me together in my mother's womb.
He's not willing for any to perish.
2 Peter 3:9 - The Lord isn't slow about keeping his promises, as some people think he is. If fact, God is patient, because he wants everyone to turn from sin and no one to be lost.
The who know him share in this by being witnesses.
Isaiah 43:10-12 - You are my witnesses and my chosen servant. I want you to know me, to trust me, and understand that I alone am God. I have always been God; there can be no others. I alone am the Lord; only I can rescue you. I promised to save you, and I kept my promise. You are my witnesses that no other god did this.
Wherever they are.
Acts 1:8 - But you will receive power when the Holy Spirit comes upon you. And you will be my witnesses, telling people about me everywhere - in Jerusalem, throughout Judea, in Samaria, and to the ends of the earth.