"The last thing Jesus said to his disciples was, "...you will be my witnesses throughout the whole world." This article presents biblical ideas and implications about what it means to be a witness.
Witnesses by God's choice
Jesus had spent hours teaching the disciples who they were. God's servants, my friends, beloved children, disciples - they were people connected to God. At moments they seemed to understand, but not completely. At the beginning of the book of Acts, just before he was about to leave them, he chose to remind them they were to be "witnesses." Throughout the rest of the book of Acts their experiences with Jesus and the words they had heard from Jesus were their constant story.
Most occurrences of the word 'witness' in the book of Acts refer to the role the eleven apostles had as 'legal witnesses' of Jesus' death and resurrection. At the end of the book, Paul uses the word of himself because he also had heard and seen the resurrected Jesus. But in Acts 1:8, when Jesus uses the term, he quotes Isaiah where the word applies broadly to all God's people. It applies to God's witnessing community.
You are my witnesses, says the LORD,
and my servant whom I have chosen,
so that you may know and believe me
and understand that I am he.
Before me no god was formed,
nor shall there be any after me.
I, I am the LORD,
and besides me there is no savior.
I declared and saved and proclaimed,
when there was no strange god among you;
and you are my witnesses, says the LORD. (Isaiah 43:10-12)
So we are witnesses by God's choice. We can not help but be witnesses when we are identified with God. And we are witnesses so that we can know God. But there is another "so that" to witness. We are witnesses "so that" others can also know God".