Jesus answered him, "Most assuredly, I tell you, unless one is born anew,{The word translated "anew" here and in John 3:7 (anothen) also means "again" and "from above".} he can't see the Kingdom of God."
Secondly, On the other hand, upright hearts, that approve themselves to God in their integrity, bid this light welcome (John 3:21): He that doeth truth cometh to the light. It seems, then, that though the gospel had many enemies it had some friends. It is a common observation that truth seeks no corners. Those who mean and act honestly dread not a scrutiny, but desire it rather. Now this is applicable to the gospel light; as it convinces and terrifies evil-doers, so it confirms and comforts those that walk in their integrity. Observe here, 1. The character of a good man. (1.) He is one that doeth truth; that is, he acts truly and sincerely in all he does. Though sometimes he comes short of doing good, the good he would do, yet he doeth truth, he aims honestly; he has his infirmities, but holds fast his integrity; as Gaius, that did faithfully (3 John 1:5), as Paul (2 Corinthians 1:12), as Nathanael (John 1:47), as Asa, 1 Kings 15:14. (2.) He is one that cometh to the light. He is ready to receive and entertain divine revelation as far as it appears to him to be so, what uneasiness soever it may create him. He that doeth truth is willing to know the truth by himself, and to have his deeds made manifest. A good man is much employed in trying himself, and is desirous that God would try him, Psalms 26:2. He is solicitous to know what the will of God is, and resolves to do it, though ever so contrary to his own will and interest. 2. Here is the character of a good work: it is wrought in God, in union with him by a covenanting faith, and in communion with him by devout affections. Our works are then good, and will bear the test, when the will of God is the rule of them and the glory of God the end of them; when they are done in his strength, and for his sake, to him, and not to men; and if, by the light of the gospel, it be manifest to us that our works are thus wrought, then shall we have rejoicing, Galatians 6:4; 2 Corinthians 1:12.