15.  To enforce this consideration, we may further observe, that the practice of religion will not only be attended with that pleasure which naturally accompanies those actions to which we are habituated, but with those supernumerary joys of heart, that rise from the consciousness of such a pleasure, from the satisfaction of acting up to the dictates of reason, and from the prospect of an happy immortality.

16.  In the fourth place, we may learn from this observation which we have made on the mind of man, to take particular care, when we are once settled in a regular course of life, how we too frequently indulge ourselves in any of the most innocent diversions and entertainments, since the mind may insensibly fall off from the relish of virtuous actions, and by degrees, exchange that pleasure which it takes in the performance of its duty, for delight of a much more inferior and unprofitable nature.

17.  The last use which I shall make of this remarkable property in human nature, of being delighted with those actions to which it is accustomed, is to shew how absolutely necessary it is for us to gain habits of virtue in this life, if we would enjoy the pleasures of the next.

18.  The state of bliss we call heaven, will not be capable of affecting those minds, which are not thus qualified for it:  we must in this world gain a relish of truth and virtue, if we would be able to taste that knowledge and perfection which are to make us happy in the next.  The seeds of those spiritual joys and raptures, which are to rise up and flourish in the soul to all eternity, must be planted in it, during this its present state of probation.  In short, heaven is not to be looked upon only as the reward, but as the natural effect of a religious life.

19.  On the other hand, those evil spirits, who by long custom, have contracted in the body, habits of lust, sensuality, malice and revenge, an aversion to every thing that is good, just, or laudable, are naturally seasoned and prepared for pain and misery.  Their torments have already taken root in them; they cannot be happy when divested of the body, unless we may suppose, that Providence will in a manner create them anew, and work a miracle in the rectification of their faculties.

20.  They may, indeed, taste a kind of malignant pleasure in those actions to which they are accustomed whilst in this life; but when they are removed from all those objects which are here apt to gratify them, they will naturally become their own tormentors, and cherish in themselves those painful habits of mind which are called, in scripture phrase, the worm which never dies.