True believers may have the assurance of their salvation shaken, diminished or discontinued in different ways. It may be:
1) Through the neglect of preserving it;
2) By falling into some special sin, which wounds the conscience, and grieves the Spirit;
3) By some sudden or intense temptation;
4) By God's withdrawing the light of his countenance; or
5) By allowing those who fear him to walk in darkness, and to have no light.
Yet, they are never utterly destitute of that seed of God, and life of faith, that love of Christ and the brethren, that sincerity of heart and conscience of duty, out of which, by the operation of the Spirit, this assurance may in due time be revived, and by the which, in the mean time, they are supported from utter despair.