2 John 1:4

“I rejoiced greatly that I found of thy children, etc.] Not all, but some of them; for good parents have not always good children, or at least not all of them; Adam had a Cain, Abraham an Ishmael, and Isaac an Esau: God is pleased to show his discriminating grace in tribes and families, by taking some, and leaving others: it is a great mercy when any are called by grace, and instead of the fathers are the children: and this was the case of some of the children of this elect lady, they were walking in the truth: in Christ, the truth, by faith, as they had received him; and in the truth of the Gospel, as they had embraced and professed it; they abode in it, and by it, and made a proficiency in…”

“I found--probably in one of his missionary tours of superintendence. See Introduction, at the end, and Jo2 1:12; Jo3 1:10, Jo3 1:14. of thy children--some. in truth--that is, in the Gospel truth. as--even as. "The Father's commandment" is the standard of "the truth."”

“I rejoiced greatly that I found ... - That I learned this fact respecting some of thy children. The apostle does not say how he had learned this. It may have been that he had become personally acquainted with them when they were away from their home, or that he had learned it from others. The word used εὕρηκα heurēka would apply to either method. Grotius supposed that some of the sons had come to Ephesus on business, and that John had become acquainted with them there. Of thy children walking in truth - That is, true Christians; living in accordance with the truth, for this constitutes the essence of religion. The expression used here, “of thy children,” (ἐκ τῶν τέκνων ek tōn…”

“I found of thy children - Probably in their aunt's house, Jo2 1:13. Walking in the truth - In faith and love. 2 John 1:5”

“1:4-11 John now applies the truth and love that he mentioned in the introduction (1:1-3) to the readers’ situation. Living in truth and love means maintaining fellowship with true Christians (1:4-6), but also discerning false teachers and refusing to listen to them or help them (1:7-11).”

“rejoiced: Phi 4:10; Th1 2:19, Th1 2:20, Th1 3:6-10; Jo3 1:3, Jo3 1:4 walking: Hos 14:9; Mal 2:6; Gal 2:14; Eph 5:2, Eph 5:8; Jo1 1:6, Jo1 1:7, Jo1 2:6 2 John 1:5”