No man can certainly know, or ought to conclude, concerning himself or others, as long as they live, that the season of grace is quite over with them. As we can conceive no rule God hath set to Himself to proceed by, in ordinary cases of this nature; so nor is there any He hath set unto us to judge by, in this case. It were to no purpose, and could be of no use to men to know so much; therefore it were unreasonable to expect God should have settled and declared any rule, by which they might come to the knowledge of it.
The Redeemer's Tears Wept Over Lost Souls (1684)
Tho none ought to conclude that their day or season of grace is quite expired, yet they ought to deeply apprehend the danger, lest it should expire before their necessary work be done and their peace made. For tho it can be of no use for them to know the former, and therefore they have no means appointed them by which to know it, 'tis of great use to apprehend the latter; and they have sufficient ground for the apprehension.