This assurance is not merely a conjectural persuasion nor even a probable persuasion based upon a fallible hope. It is an infallible assurance of faith founded on the blood and righteousness of Christ revealed in the gospel. It is also founded upon the inward evidence of those graces of the Spirit in connection with definite promises made in the Scriptures, and also on the testimony of the Spirit of adoption who witnesses with our spirits that we are the children of God, and who uses the experience of assurance to keep our hearts both humble and holy.