Always learning, while yet they never can come to the knowledge of the truth That fluctuation between various desires, of which he now speaks, is when, having nothing solid in themselves, they are tossed about in all directions. They "learn," he says, as people do who are under the influence of curiosity, and with a restless mind, but in such a manner as never to arrive at any certainty or truth. It is ill-conducted study, and widely different from knowledge. And yet such persons think themselves prodigiously wise; but what they know is nothing, so long as they do not hold the truth, which is the foundation of all knowledge.

Ever learning - That is, these "silly women;" for so the Greek demands. The idea is, that they seeM to be disciples. They put themselves wholly under the care of these professedly religious teachers, but they never acquire the true knowledge of the way of salvation.
And never able to come to the knowledge of the truth - They may learn many things, but the true nature of religion they do not learn. There are many such persons in the world, who, whatever attention they may pay to religion, never understand its nature. Many obtain much speculative acquaintance with the "doctrines" of Christianity, but never become savingly acquainted with the system; many study the constitution and government of the church, but remain strangers to practical piety; many become familiar with the various philosophical theories of religion, but never become truly acquainted with what religion is; and many embrace visionary theories, who never show that they are influenced by the spirit of the gospel. Nothing is more common than for persons to be very busy and active in religion, and even to "learn" many things about it, who still remain strangers to the saving power of the gospel.

Ever learning - From their false teachers, and never able to come to the knowledge of the truth, because that teaching never leads to the truth; for, although there was a form of godliness, which gave them a sort of authority to teach, yet, as they denied the power of godliness, they never could bring their votaries to the knowledge of the saving power of Christianity.
There are many professors of Christianity still who answer the above description. They hear, repeatedly hear, it may be, good sermons; but, as they seldom meditate on what they hear, they derive little profit from the ordinances of God. They have no more grace now than they had several years ago, though hearing all the while, and perhaps not wickedly departing from the Lord. They do not meditate, they do not think, they do not reduce what they hear to practice; therefore, even under the preaching of an apostle, they could not become wise to salvation.

Ever learning,.... Some new notion and practice or another: and never able to come to the knowledge of the truth; partly because of the teachers, which they heap up to themselves, who are unapt to teach, are blind and ignorant guides, and know not the truth, but are enemies to it, and resist it; and partly because of themselves, the sins they are laden, and the lusts they are led away with, which hinder them from coming to the knowledge of the truth.

Ever learning--some new point, for mere curiosity, to the disparagement of what they seemed to know before.
the knowledge--Greek, "the perfect knowledge"; the only safeguard against further novelties. Gnosticism laid hold especially of the female sex [ESTIUS, 1.13.3]: so Roman Jesuitism.

Ever learning - New things. But not the truth of God.