And there shall in no wise enter into it any thing that defileth, neither whatsoever worketh abomination, or maketh a lie: but they which are written in the Lamb's book of life. There shall in nowise enter into it any thing that defileth - See Isaiah 35:8; Isaiah 52:1. Neither an impure person - he who turns the grace of God into lasciviousness, nor a liar - he that holds and propagates false doctrines.
But they which are written - The acknowledged persevering members of the true Church of Christ shall enter into heaven, and only those who are saved from their sins shall have a place in the Church militant.
All Christians are bound by their baptism to renounce the devil and all his works, the pomps and vanities of this wicked world, and all the sinful lusts of the flesh; to keep God's holy word and commandments; and to walk in the same all the days of their life. This is the generation of them that seek thy face, O God of Jacob! Reader, art thou of this number? Or art thou expecting an eternal glory while living in sin? If so, thou wilt be fearfully disappointed. Presuming on the mercy of God is as ruinous as despairing of his grace. Where God gives power both to will and to do, the individual should work out his salvation with fear and trembling.
Commentary on the Bible, by Adam Clarke [1831].