WCF xviii:2 This certainly is not a bare conjectural and probable persuasion, grounded upon a fallible hope; but an infallible assurance of faith, founded upon the divine truth of the promises of salvation, the inward evidence of those graces unto which these promises are made, the testimony of the Spirit of adoption witnessing with our spirits that we are the children of God: which Spirit is the earnest of our inheritance, whereby we are sealed to the day of redemption.
As someone who is suffering from a lack of assurance, are the following three separate witnesses and how ought I be assured by them?
A. "promises of salvation"
B. "inward evidence"
C. "the testimony of the Spirit"
As an aside, what do you think about personal covenanting as advocated by William Guthrie?
Q. 13 How shall I be sure that my heart does accept of God's offer, and does close with Christ Jesus? .
A. Go make a covenant expressly, and by word speak the thing unto God.
Q. 14 What way shall I do that?
A. Set apart some portion of time, and, having considered your own lost estate, and the remedy offered by Christ Jesus, work up your heart to be pleased and close with that offer, and say unto God expressly that you do accept of that offer, and of Him to be your God in Christ; and do give up yourself to Him to be saved in His way, without reservation or exception in any case; and that you henceforth will wait for salvation in the way He has appointed.