For further direction and caution in this matter, the believer would take notice of these particulars:
1. That he should not sit down upon any measure of knowledge he hath attained to, or can attain to here, as if he had enough, and should labour for no more; but he should still be minding his duty of seeking, and pressing for more.
2. Whenever he is about any mean of knowledge, such as preaching, reading, conference, &c. his heart should be only upon Christ. He should be hanging on his lips for a word of instruction; and with greediness looking for a word from his mouth; he should be sending many posts to heaven, many ejaculatory desires for light and understanding, and that with singleness and sincerity, and not for base ends, or out of hypocrisy.
3. Let him not think, that there is no growth in knowledge, because possibly he perceiveth it not, or is not satisfied as to the measure thereof; yea, though possibly he perceive more ignorance, than ever he did before. If he grow in the knowledge of his own ignorance, it is a growth of knowledge not to be despised; and in a manner, what can we else know of God, but that he far transcendeth all our knowledge, and that he is an incomprehensible one, in all his ways.
4. Let him not think, that there is no growth in knowledge, because he perceiveth not a growth in the knowledge of such or such a particular, which he desireth most; for if there be a truth in the knowledge of other particulars, necessary to be known, there is no reason to complain. If one grow not, as he supposeth, in the knowledge of God, and of the mysteries of the gospel; yet if he grow in the discovery of the treachery and wickedness of his own heart, he cannot say that he groweth not in knowledge.
5. Let him not measure his growth in knowledge, by his growth in the faculty of speaking and discoursing of such or such points of religion; many measure their knowledge by their tongue, and think they know little, because they can express little; and so they think they attain to no increase or growth in knowledge, because they perceive no increase or growth in this faculty of discoursing, and talking of such or such points of truth. It is safer to measure their knowledge by the impression that the truth hath on their spirits, and the effects of it on all their carriage, than by their ability and skill to talk and dispute of it.
6. Let them beware to imagine, that they shall be able to search out the Almighty unto perfection, "Canst thou (said Zophar, Job. xi. 7, 8, 9.) by searching find out God? canst thou find out the Almighty unto perfection? He is as high as heaven, what canst thou do? deeper than hell, what canst thou know? The measure thereof is longer than the earth, and broader than, the sea." Or that they shall be able ever to win to the bottom of their own false deceitful heart, which, as Jeremiah saith, chap. xvii. 9, "Is deceitful above all things, and desperately wicked; who can know it?" and which it is God's prerogative alone to search and try, ver. 10. Neither let them think, so long as they are here, to win to an exact and perfect knowledge of the mysteries of God, wherein is the manifold wisdom of God, Eph. iii. 10, which very principalities and powers in heavenly places are learning; and which the angels are poring and looking into with desire, 1 Pet. i. 12. There is no perfection in knowledge to be had here; for here the best but knoweth in part, and prophesieth in part, 1 Cor. xiii. 4.
7. Let them not think that every one shall have the same measure of knowledge; every one hath not the like use for it, or the like capacity for it. There is a measure proportioned to every one; they should not then complain, because they have not such a measure of knowledge as they perceive in some others. It may be, the Lord hath some harder piece of service, which calleth for more knowledge, to put others to. Let every one then mind his duty faithfully and conscientiously, and let him not quarrel with God, that he attaineth not to such a measure of knowledge as he seeth others attain unto.
8. Neither let them think, that the same measure is required of all. For more is required of some, by reason of their office and charge in the house of God, being called to teach and instruct others; and so more is required of such, as have larger capacities, and a better faculty of understanding than others, who naturally are but of a narrow reach, and of a shallow capacity. More also is required of such as live under plain, powerful, and lively ordinances, and under a more powerful and spiritual dispensation of the grace of God, than of others that want such advantages. So likewise, more is required of old Christians than of new beginners; old men, of much and long experience, should know more than such as are but babes in Christ and but of yesterday.
9. Let their desires run out after that knowledge, not which puffeth up,—for there is a knowledge which puffeth up, 1 Cor. viii. 1,—but which humbleth, and driveth the soul farther from itself and nearer to Christ.