That they should seek the Lord - This is a conclusion drawn from the preceding statement. God, who is infinitely great and self-sufficient, has manifested himself as the maker of the world, the creator, preserver, and governor of men. He has assigned them their portion, and dispensed to them their habitations, and the various blessings of his providence, to the end that they should seek him in all his works.

Feel after him - Ψηλαφησειαν αυτον, That they might grope after him, as a person does his way who is blind or blindfolded. The Gentiles, who had not a revelation, must grope after God, as the principle of spiritual life, that they might find him to be a Spirit, and the source of all intellectual happiness; and the apostle seems to state that none need despair of finding this fountain of goodness, because he is not far from every one of us.

they.

Acts 15:17 That the residue of men might seek after the Lord, and all the Gentiles, on whom my name is called, said the Lord...

Psalm 19:1-6 The heavens declare the glory of God; and the firmament shows his handiwork...

Romans 1:20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made...

Romans 2:4 Or despise you the riches of his goodness and forbearance and long-suffering...

he be.

Acts 14:17 Nevertheless he left not himself without witness, in that he did good, and gave us rain from heaven, and fruitful seasons...

1 Kings 8:27 But will God indeed dwell on the earth? behold, the heaven and heaven of heavens cannot contain you...

Psalm 139:1-13 O lord, you have searched me, and known me...

Jeremiah 23:23,24 Am I a God at hand, said the LORD, and not a God afar off...

The Man who is Judge
...He will judge the world in righteousness by that Man whom He hath ordained; whereof He hath given assurance unto all men, in that He hath raised Him from the dead.'--ACTS xvii. 31. I. The Resurrection of Jesus gives assurance of judgment. (a) Christ's Resurrection is the pledge of ours. The belief in a future life, as entertained by Paul's hearers on Mars Hill, was shadowy and dashed with much unbelief. Disembodied spirits wandered ghostlike and spectral in a shadowy underworld. The belief …
Alexander Maclaren—Expositions of Holy Scripture: The Acts

Immortality of the Soul, and a Future State.
--Inter silvas academi quærere verum. Hor. lib. II. epist. 2. v. 45. To search out truth in academic groves. THE course of my last speculation [3] led me insensibly into a subject upon which I always meditate with great delight, I mean the immortali …
Joseph Addison—The Evidences of the Christian Religion, with Additional Discourses

Repentance and Restitution.
"God commandeth all men everywhere to repent."--Acts xvii. 30. Repentance is one of the fundamental doctrines of the Bible. Yet I believe it is one of those truths that many people little understand at the present day. There are more people to-day in the mist and darkness about Repentance, Regeneration, the Atonement, and such-like fundamental truths, than perhaps on any other doctrines. Yet from our earliest years we have heard about them. If I were to ask for a definition of Repentance, a great …
Dwight L. Moody—The Way to God and How to Find It