THIRD, That every believer should not only be careful that their works be good, and for the present do them, but should also be careful to maintain them; that is, they should carefully study to keep in a constant course of good works.
FOURTH, and lastly, That the best way to provoke both ourselves and others to this work, it is to be often affirming to others the doctrine of justification by grace, and to believe it ourselves: 'This is a faithful saying, and these things I will,' saith Paul, 'that thou affirm constantly, that they which have believed in God might be careful to maintain good works.'
FIRST. I begin with the first. That good works do flow from faith.
This is evident divers ways.
First, From the impossibility of their flowing from any other thing; they must either flow from faith, or not at all: 'For whatsoever is not of faith, is sin' (Rom 14:23). And again, 'Without faith it is impossible to please him' (Heb 11:6). Every man by nature, before faith, is an evil and a corrupt tree; and a corrupt tree cannot bring forth good fruit: 'Do men gather grapes of thorns, or figs of thistles?' (Matt 7:16,17). Now a man is made good by faith, and by that bringeth forth the fruits that are acceptable to God (Heb 11:4; Col 1:4-6).
Wherefore sinners, before faith, are compared to the wilderness, whose fruits are briars and thorns; and whose hearts are the habitation of dragons; that is, of devils 4 (Isa 35:6,7; Heb 6:7,8).
And hence again it is, that they are said to be Godless, Christless, Spiritless, faithless, hopeless; without the covenant of grace, without strength; enemies in their minds by wicked works, and possessed by the spirit of wickedness, as a castle by a conqueror (Eph 2:12; Jude 19; 2 Thess 3:2; Col 1:21; Luke 11:21).
Now, these things being thus, it is impossible that all the men under heaven, that are unconverted, should be able to bring forth one work rightly good; even as impossible, as for all the briars and thorns under heaven to bring forth one cluster of grapes, or one bunch of figs; for indeed they want the qualification. A thorn bringeth not forth figs, because it wanteth the nature of the fig-tree; and so doth the bramble the nature of the vine. Good works must come from a good heart. Now, this the unbeliever wanteth, because he wanteth faith; for it is that which purifieth the heart (Luke 6:45; Acts 15:9). Good works must come from love to the Lord Jesus; but this the unbeliever wanteth also, because he wanteth faith: For faith 'worketh by love,' and by that means doth good (Gal 5:6).
And hence again it is, that though the carnal man doth never so much which he calleth good, yet it is rejected, slighted, and turned as dirt in his face again; his prayers are abominable (Prov 15:8), his ploughing is sin (Prov 21:4), and all his righteousness as menstruous rags (Isa 64:6).
Thus you see that without faith there are no good works.
Now then, to show you that they flow from faith: and that, For that FAITH is a principle of life, by which a Christian lives (Gal 2:19,20), a principle of motion, by which it walks towards heaven in the way of holiness (Rom 4:12; 2 Cor 5:7). It is also a principle of strength, by which the soul opposeth its lust, the devil, and this world, and overcomes them. 'This is the victory, even our faith' (1 John 5:4,5) Faith, in the heart of a Christian, is like the salt that was thrown into the corrupt fountain, that made the naughty waters good, and the barren land fruitful (2 Kings 2:19-22). Faith, when it is wrought in the heart, is like leaven hid in the meal, (Matt 13:33) or like perfume that lighteth upon stinking leather, turning the smell of the leather into the savour of the perfume; faith being then planted in the heart, and having its natural inclination to holiness. Hence it is that there followeth an alteration of the life and conversation, and so bringeth forth fruit accordingly. 'A good man out of the good treasure of his heart bringeth forth that which is good' (Luke 6:45). Which treasure, I say, is this faith (James 2:5; 1 Peter 1:7). And therefore it is that faith is called 'the faith according to godliness,' (Titus 1:1) and the 'most holy faith' (Jude 20).