As the community is to bear up bravely under persecution, so it is to watch carefully over the purity of its own life. There must be no strife or dissension; above all, there must be moral consecration, for without this it is impossible to hold fellowship with Christ (Hebrews 12:14). The church must therefore keep anxious guard over its members, and make sure that each one of them lives up to his Christian profession. Even a single unworthy member may be like a poisonous weed, tainting the whole atmosphere round about (Hebrews 12:15). The Church must be specially watchful against men who indulge in sensual sins, or who live solely for worldly and material interests, careless, like Esau, of that higher destiny to which God has called them. Esau's later repentance did not avail him, and when he would fain have received the blessing he found that it was gone from him for ever. [Note that it was not the place of repentance, but the blessing, which Esau sought diligently with tears and failed to secure. A. J. G.] It may be, however, that the writer is also reverting to the idea of Hebrews 6:4 ff. For those who have fallen into grave sin after their conversion there can be no repentance, and they must be excluded from the Christian community.
Related Commentaries of Hebrews 12:14
Hebrews 12:14-17
14 Follow peace with all men, and holiness, without which no man shall see the Lord:
15 Looking diligently lest any man faild of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled;
16 Lest there be any fornicator, or profane person, as Esau, who for one morsel of meat sold his birthright.
17 For ye know how that afterward, when he would have inherited the blessing, he was rejected: for he found no placee of repentance, though he sought it carefully with tears.