The promise. The highest blessedness is to know God John 17:3. If any distinction between "the Lord" יהוה yehovâh and "God" אלהים 'elohı̂ym can be pressed here, it is that in the former the personality, in the latter the glory, of the divine nature is prominent.

Then shalt thou understand the fear of the LORD, and find the (e) knowledge of God.
(e) This (he says) is the true wisdom to know and fear God.

Then shalt thou understand the fear of the Lord,.... The grace of fear, and the exercise of it: which is the beginning of wisdom and knowledge, and is a treasure itself, Proverbs 1:7. By means of the Gospel the Lord works it in the hearts of his people by his Spirit; and by the same leads them into the riches of his special grace and "goodness", which they are influenced by to "fear", and the Lord for the sake of it: and particularly they are led hereby to the pardoning grace and mercy of God, which is with him, that he may "be feared"; and it is the Gospel which induces and encourages a true filial fear of God, by which men "depart from evil"; for that teaches them to deny all manner of sin, and to live a godly life and conversation: so that through a diligent search after the knowledge of the Gospel, and an attaining it, men come to have a spiritual, experimental, and practical understanding of the fear of God as a grace; and also, as it includes the whole worship of God, by means of Gospel light, they come to understand what sort of worship that is God is to be worshipped with; that it is pure, spiritual, and evangelical, suited to his nature and will: what the ordinances of divine service are; and that these are to be kept as they were delivered, and in the exercise of faith, from a principle of love, and with a view to the glory, of God, without trusting to them or depending on them for salvation. And this is the advantage arising from a diligent search after the doctrine of wisdom, or the Gospel, and a knowledge and understanding of it; and is used as an argument encouraging to it; and another follows;
and find the knowledge of God; such a knowledge of God as is not to be found by the light of nature, in the whole volume of the creatures, and in all the writings of the philosophers; no, nor in the law of Moses; for though much of God and his perfections may be seen and known by the things that are made, and much of the will of God by the law he gave; yet by neither of these is the knowledge of God in Christ, which is "life eternal". This only is to be found in the Gospel, and by means of it; here only it is brought to light; and through this men not only find it, but increase more and more in it: herein is a glorious display of his persons and perfections, of his counsels and purposes, of his covenant and promises, of his mind and will, with respect to doctrine and worship; and of the way of peace, life, and salvation, by Jesus Christ; which must serve greatly to engage and excite persons to a diligent search and pursuit after it. And all that is here said is designed to encourage a diligent search after divine things; for, as the poet (n) says, there is nothing so difficult but by searching may be found out.
(n) Terent. Heautont. Acts. 4. Sc. 1.

understand--or, "perceive intelligently."
find--obtain.