The veil of flesh and blood divides us from the world of spirits; we know not the manner of their life in the state of separation: we are at an utter loss as to their stations and residences; what relation they bear to any part of this material creation; whether they dwell in thin airy vehicles, and are inhabitants of some starry world, or planetary region; or whether they subsist in their pure intellectual nature, and have nothing to do with any thing corporeal, till their dust be recalled to life. We are unacquainted with the laws by which they are governed, and the methods of their converse: we know little of the businesses they are employed in, those glorious services for their God and their Saviour, in which they are favoured with assistant angels; and little are we acquainted with their joys, which are unspeakable and full of glory. The very language of that world, is neither to be spoken nor understood by us; St. Paul heard some of the words of it, and had a faint glimpse of the sense of them; but he could not repeat them again to mortal ears; nor had he power, nor leave to tell us the meaning of them; 2 Cor. xii. 4. For, _whether he was in the body, at that time, or out of the body_, he himself was not able to determine. And as for the heaven of the resurrection; what sort of bodies shall be raised from the dust, for perfect spirits to dwell in, is as great a secret. A spiritual body is a mystery to the wisest divines and philosophers; where our habitation shall be, and what our special employment through the endless ages of immortality, are among the hidden unsearchables. The most that we know, is, that we shall be made like to Christ, and we shall be where he is, to behold his glory; 1 John iii. 2. and John xvii. 24. If the eternal life of the saints be so much a secret at present, we may draw these two or three inferences from it. I. Inference. How necessary is it for a christian to keep faith awake and lively, that he may maintain his acquaintance with the spiritual and unseen world! It is faith that converses with invisibles: _faith is the substance of things hoped for, and the evidence of things not seen_; Heb. xi. 1. It is faith that deals in hidden traffic, and grows rich in treasures that are out of sight. It is by faith in the Son of God, we live this spiritual life, by faith in an absent Saviour; Gal. ii. 20. _Whom having not seen we love; and though we see him not, yet believing, we rejoice_; 1 Pet. i. 8. Let the christian, therefore, maintain a holy jealousy, lest too much converse with the things of sense, dull the eye of his faith, or weaken the hand of it. Let him put his faith into perpetual exercise, that he may live within the view of those glories that are hidden from sense; that he may keep his hold of eternal life; that he may support his hopes, and secure his joys. Until we can live by sight, let us _walk by faith_; 2 Cor. v. 7.