By all this you may perceive, that those troubled christians which doubt not of the truth of the word of God, but only of their own sincerity, and consequently of their justification and salvation, do ignorantly complain that they have not faith, or that they cannot believe: for it is no act of unbelief at all, for me to doubt whether my own heart be sincere: this is my ignorance of myself, but it is not any degree of unbelief; for God's word doth no where say that I am sincere, and therefore I may doubt of this, without doubting of God's word at all. And let all troubled christians know, that they have no more belief in them, than they have doubting or unbelief of the truth of the word of God. Even that despair itself, which hath none of this in it, hath no unbelief in it (if there be any such). I thought it needful thus far to tell you what unbelief is, before I come to give you directions against it. And though the mere doubting of our own sincerity be no unbelief at all, yet real unbelief of the very truth of the holy Scriptures, is so common and dangerous a sin, and some degree of it is latent in the best, that I think we can no way so much further the work of grace, as by destroying this. The weakness of our faith in the truth of Scriptures, and the remnant of our unbelief of it, is the principal cause of all the languishings of our love and obedience, and every grace; and to strengthen faith, is to strengthen all. What I have fullier written in my "Saints' Rest," part 2, and my "Treatise against Infidelity," I here suppose.
_Direct._ I. Consider well how much of religion nature itself teacheth, and reason, (without supernatural revelation,) must needs confess: (as, that there is another life which man was made for, and that he is obliged to the fullest love and obedience to God, and the rest before laid down in the Introduction.) And then observe how congruously the doctrine of Christ comes in, to help where nature is at a loss, and how exactly it suits with natural truths, and how clearly it explaineth them, and fully containeth so much of them as is necessary to salvation; and how suitable and proper a means it is to attain their ends; and how great a testimony the doctrines of nature and grace do give unto each other.[137]
_Direct._ II. Consider, that man's end being in the life to come, and God being the righteous and merciful Governor of man in order to that end, it must needs be that God will give him sufficient means to know his will in order to that end; and that the clearest, fullest means must needs demonstrate most of the government and mercy of God.
_Direct._ III. Consider, what full and sad experience the world hath of its pravity and great corruption; and that the natural tendency of reason is to those high and excellent things, which corruption and brutishness do almost extinguish or cast out with the most; and that the prevalency of the lower faculties against right reason, is so lamentable and universal, to the confusion of the world, that it is enough to tell us, that this is not the state that God first made us in, and that certainly sin hath sullied and disordered his work. The wickedness of the world is a great confirmation of the Scripture.
_Direct._ IV. Consider, how exactly the doctrine of the gospel, and covenant of grace, are suited to the lapsed state of man; even as the law of works was suited to his state of innocency: so that the gospel may be called the law of lapsed nature, as suited to it, though not as revealed by it; as the other was the law of entire nature.
_Direct._ V. Compare the many prophecies of Christ, with the fulfilling of them in his person. As that of Moses recited by Stephen, Acts vii. 37; and Isa. lviii; Dan. ix. 24-26, &c. And consider that those Jews which are the christians' bitterest enemies, acknowledge and preserve those prophecies, and all the Old Testament, which giveth so full a testimony to the New.
_Direct._ VI. Consider, what an admirable suitableness there is in the doctrine of Christ, to the relish of a serious, heavenly mind: and how all that is spiritual and truly good in us, doth close with it and embrace it from a certain congruity of natures, as the eye doth with the light, and the stomach with its proper food. Every good man in reading the holy Scripture, feeleth something (even all that is good) within him bear witness to it. And only our worse part is quarrelling with it, and rebels against it.