We must remember that holiness, at root, means being set apart. To pursue holiness thus means to set ourselves apart from sin, from self-focus, from being too interested in the things of this world. We have Esau as a negative example of holiness, as he elevated the things of this world above the spiritual blessings God had promised Abraham and Isaac. But holiness also means being set apart for God, devoting ourselves completely to Him and to His glory. Again, we have a negative example – that of bitterness. Bitterness usually comes when we turn away from God because He does not choose to bless us in some way that we think we deserve. Instead of giving ourselves over to worldliness or bitterness, we must cling to the grace of God, remembering that we do not deserve anything He has given us, and trusting that He loves us and always knows what is best for us.

14 Follow peace with all men, and holiness, without which no man shall see the Lord:
15 Looking diligently lest any man fail 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 place of repentance, though he sought it carefully with tears.
(Heb. 12:14-17 KJV)