Your testimony of God's grace

What does it mean to 'give your testimony'? Considering various scriptural suggestions, and particular our Lord's command to the cleansed Gadarene demoniac, we conclude that it is your story of God's grace in Christ—personal details around a common core, what great things the Lord has done for you and how he has had compassion upon you. It is a story which brings glory to God and demonstrates to God's people that you too, by grace, in Christ, have become one of them.