For many Christians, finding a well-grounded assurance can be a tremendous struggle. As ever, John Newton provides sound pastoral wisdom on how to grow in a firm sense that we are Christ's and that Christ is ours. For those familiar with this experiential Calvinist, there will be no surprise to discover that, as with every other upward rung on the ladder of spiritual growth, we learn this lesson in the school of hard knocks and in the experiential grace of actually feeding on Christ for ourselves....

When young Christians are greatly comforted with the Lord’s love and presence, their doubts and fears are for that season at an end. But this is not assurance; so soon as the Lord hides his face they are troubled, and ready to question the very foundation of hope. Assurance grows by repeated conflict, by our repeated experimental proof of the Lord’s power and goodness to save; when we have been brought very low and helped, sorely wounded and healed, cast down and raised again, have given up all hope, and been suddenly snatched from danger, and placed in safety; and when these things have been repeated to us and in us a thousand times over, we begin to learn to trust simply to the word and power of God, beyond and against appearances: and this trust, when habitual and strong, bears the name of assurance; for even assurance has degrees
— Newton, J., & Cecil, R. (1824). The Works of John Newton (Vol. 2, p. 176). London: Hamilton, Adams & Co.