A witness is important. Why? Because they give evidence or proof of something that has taken place. Without a witness, it's difficult to determine what is true and what is false. Throughout history God has provided witnesses to reveal and confirm His truth, culminating in His Son, Jesus Christ whose life, death, and resurrection brought salvation to the world.
Before His death and resurrection, Jesus promised that He would send the Holy Spirit who would be at work in the lives of His followers, bearing witness to the truth and helping them to be His witnesses. The book of Acts describes how God's Spirit empowered and equipped His people to be His witnesses by spreading His gospel and building His Church. As we will see, the same Spirit that was at work in the first century is still at work in His followers today. Through Him, we are able to be Christ's witnesses for His glory and the advancement of His gospel.