TESTIFY: to give a testimony of how God has been good. To prove or demonstrate something is true.
A testimony is a powerful tool in sharing what God has done and is continuing to do in our lives. Our testimony can bring others to Him when we share them.
In Mark 5:19, Jesus said to the Samaritan woman at the well, “No, go home to your family, and tell them everything the Lord has done for you and how merciful he has been.”
When God has brought you through, blessed you, or shown you grace and mercy, your first response should be to treasure your breakthrough or blessing and be grateful for it. But then your next response should be to share it with others. God's goodness is meant to be shared as often as possible.