"and they shall be all taught of God; by his Spirit to know themselves, and Jesus Christ; that is, all that are ordained to eternal life; all that are given to Christ, and are chosen in him; all the children of Zion, and who are the children of God; these are all, sooner or later, in a special manner, taught of God: and which does not intend mere external instructions, and objective teachings by the ministry of the word, for many are so taught, who never come to Christ; but special teachings, such as are attended with the energy of divine grace, and the power of the Spirit of God, who guides into all truth, savingly and spiritually: for this is to be understood of their being taught in the Gospel of Christ, and not in the law"
"But our Lord, by these words, instructs us, and would have us observe, that all that the Father hath given him, whether Jews or Gentiles, of whom he had been speaking in the preceding verses, should be taught of God; and so taught, as to be drawn and brought to him, and believe in him, and have everlasting life: wherefore he infers from hence, that every man, whether a Jew or a Gentile, that is taught of God, will come to him in a spiritual way, and trust in him for eternal life and happiness, as follows: every man therefore that hath heard, and hath learned of the Father, cometh unto me; everyone that has heard the voice of the Father's love, grace, and mercy in the Gospel, and has learned of him the way of peace, life, and salvation by Christ, under the influence of his grace, comes unto Christ; being encouraged by the declarations and promises of grace he has heard and learned, and ventures his soul on Christ, and commits it to him; trusting and relying on his person, blood, righteousness, and sacrifice, for justification, pardon, atonement, acceptance with God, and eternal life."
- from John Gill's Bible commentary on John 6:45