Adam Clarke on 1 John 2:28

And now, little children - Τεκνια, Beloved children, abide in him - in Christ Jesus. Let his word and spirit continually abide in you, and have communion with the Father and the Son.

That when he shall appear - To judge the world, we may have confidence, παρῥησιαν, freedom of speech, liberty of access, boldness, from a conviction that our cause is good, and that we have had proper ground for exultation; and not be ashamed - confounded, when it appears that those who were brought to Christ Jesus, have apostatized, and are no longer found in the congregation of the saints, and consequently are not our crown of rejoicing in the day of the Lord Jesus. Abide in him, that this may not be the case.