Ans. 1. Seeing all these are, and may be known, as you yourself confess, by them that have not the gospel; and I add, nor yet the Holy Ghost, nor any saving knowledge of God, or eternal life: Therefore it cannot be the design of Jesus Christ by the gospel to promote or help forward this knowledge, simply from this principle, viz. Natural light, and the dictates of it. My reason is, because when nature is strained to the highest pin, it is but nature still; and so all the improvement of its light and knowledge is but an increase of that which is but natural. 'But [saith Paul] the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned' (1 Cor 2:14).
But the gospel is the ministration of the Spirit; a revelation of another thing than is found in, or can be acquired by, heathenish principles of nature.
I say, a revelation of another thing; or rather, another discovery of the same. As, 1. Concerning the Godhead; the gospel giveth us another discovery of it, than is possible to be obtained by the dictates of natural light; even a discovery of a trinity of persons, and yet unity of essence, in the same Deity (1 John 5:1,5,8). 2. The light of nature will not shew us, that God was in Christ, reconciling the world to himself. 3. The light of nature will not shew us, that we owe what we are, and have, to God, because we are the price of the blood of his Son. 4. The light of nature will not shew, that there is such a thing as election in Christ. 5. Or, that there is such a thing, as the adoption of children to God, through him. 6. Nor, that we are to be saved by faith in his blood. 7. Or, that the man Christ shall come from heaven to judgment. These things, I say, the light of nature teacheth not; but these things are the great and mighty things of the gospel, and those about which it chiefly bendeth itself, touching upon other things, still as those that are knowable, by a spirit inferior to this of the gospel.
Besides, as these things are not known by the light of nature, so the gospel, when it comes, as I also told you before, doth implant in the soul another principle, by which they may be received, and from which the soul should act and do, both towards God and towards men; as namely the Holy Ghost, faith, hope, the joy of the Spirit, &c.
The other things you mention, viz.
1. 'The immorality of the soul' (p. 138).
2. 'The doctrine of rewards and punishments in the life to come' (p. 140).
3. 'Of the forgiveness of sin upon true repentance,' &c. (p. 142).
[4. The doctrine of God's readiness to assist men by his special grace in their endeavours after virtue (p. 143).]
Ans. All these things may be assented to, where yet the grace of the gospel is not, but yet the apprehension must be such, as is the light by which they are discovered; but the light of nature cannot discover them, according to the light and nature of the gospel; because the gospel knowledge of them, ariseth also from another principle: So then, These doctrines are not confirmed by the gospel, as the light of nature teacheth them: Wherefore, Paul, speaking of the things of the gospel, and so consequently of these, he saith, 'Which things also we speak, NOT in the WORDS which MAN'S wisdom teacheth, but which the HOLY GHOST teacheth; comparing spiritual things with spiritual' (1 Cor 2:13). As if he should say, We speak of God, of the soul, of the life to come, of repentance, of forgiveness of sins, &c. Not as philosophers do, nor yet in their light; but as saints, Christians, and sons of God, as such who have received, not the spirit of the world, but the spirit which is of God; that we may know the things that are freely given to us of God.