Grace may be said to be weak, either when a lower or less degree thereof is compared with a higher and greater degree of the same; or it may be said to be weak when, in what degree of it you will, it shall be engaged by, or engage itself against sin, &c.
There are degrees of grace in the world, some have less, and some bigger measures thereof, and according to the measure of grace received, so is a Christian capable of action. He that has little, acts but weakly; he that has much, acts more strongly; and he of the saints that has most, acteth best of all: but yet none of these three can act so as they should and would, and, consequently, so depart from iniquity as is their duty. Witness those four that I mentioned but now, for they are among the first-rate of saints, yet you see what they did, and hear what they said.
Sin is a mighty tyrant; it is also installed in our flesh, and has moreover that in it which suiteth with whatever is sensual in us. The flesh relisheth it well, though the spirit of the Christian is against it.
Sin is an active beast, and will not admit that the soul should attempt to put forth itself in any good thing, without opposition and contradiction. 'When I should do good evil is present with me.'[6]
Sin is of a polluting and defiling nature, and what grace soever it toucheth it staineth, and in staining makes it weaker, than were it not so defiled it would be. Besides, not a grace, nor an act of grace in the soul can escape untouched.
Unbelief stands ready to annoy faith in the grace, as well as in the act of faith.
Hardness of heart will not let love so affectionately and sympathisingly act as it should.
Sense and reason being polluted will not let hope be so steadfastly fixed upon unseen things as it should.
Pride will not let us be so humble as we ought, nor self so self denying. Passion often interrupts our patience, and angry motions our meekness. By these, and more that might be named, it appears that sin is in us, opposeth our graces, and letteth[7] them from acting as they should; and because this sin has part of ourself in its possession, therefore though our more noble part be utterly against it, yet we depart not from it as we should.
God chargeth Moses with rash and unadvised words, and so he doth
Job also: Daniel did wear the name of an idol god, and Paul freely
confesseth himself unfirm. (Num. 20:12; Psa. 106:32; Job 38:2;
Job 42:6; Dan. 4:8; Rom. 7:24)