ourselves from those things which would destroy life, and use all proper means of preserving it : so neither can we, of ourselves, preserve the life of our souls ; yet are we hound to " keep our heart with all dili- gence ; since out of it are the issues of life."
It is indeed supposed here, that a new heart has been given to us ; because from the unregenerated heart no good thing can issue: but inasmuch as even the renewed heart has still innumerable corruptions within it, we must keep it with all diligence.
To impress this duty on our minds, let us consider,
I. The duty enjoined —
"To keep the heart" is indeed an arduous task. To assist you in the performance of it, we will offer such suggestions as appear suitable to the occasion :
1. Fortify it with good principles —
[A city unfortified is open to assault on every side : and so is the heart, if not duly fortified by the principles of true religion. As a sinner redeemed by the precious blood of Christ, and sanctified by his Spirit, I am the Lord's peculiar property : I live by him ; and I must live for him : " having been bought with a price, I am not my own, but his" who bought me : and I have nothing to do but to " glorify him with my body and my spirit, which are his." When therefore any thing attempts to gain possession of my heart, I must keep it for Him ; for Him wholly ; for Him alone. Nothing is to break in upon this principle. Let earth and heU assault me, I must oppose them in this impregnable bulwark ; " Depart from me, ye evil-doers; I will keep the commandments of my God''." The Christian is furnished by God with armour for this con- test''; and, clothed in this panoply, he must maintain the conflict even unto death "^.j
2. Watch all its most secret motions —
[A citadel, however strong, if filled with traitors waiting for an occasion to open it to the enemy, needs to be guarded with peculiar care : the professed defenders of it must them- selves be watched. So it is with the heart, notwithstanding it be at present garrisoned for the Lord. It is inconceivably difficult in many instances to distinguish between the loyal and the treacherous. They are both habited in the same uni- form ; and both make the very same professions : both too appear actuated by the same holy zeal. The Apostles, when
a Ps. cxix. 115. b Eph. vi. 11— IG. ^ Rev. ii. 10.