But solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil. Hebrews 5:14 (ESV)
In the author’s warning against apostasy, we see a rebuke against unwarranted immaturity in understanding the truth of God’s word. We must apply ourselves to the studying, thinking about and understanding of God’s word for our own growth and so we can effectively share with others
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt. Hebrews 6:4–6 (ESV)
The warning against apostasy is a serious one, those around the things of God and who know the truth of the Gospel but consciously reject the truth leave themselves in a potion that means they can not be restored (or saved in the first place) because there is only one way and they have rejected that way…. there is on Gospel version 2, there is only 1.
Though we speak in this way, yet in your case, beloved, we feel sure of better things—things that belong to salvation. Hebrews 6:9 (ESV)
This distinguishes the true believers who have salvation from the group of church goers / false converts mentioned above
so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us. Hebrews 6:18 (ESV)
We have assurance and security in our salvation because of who God is
(for the law made nothing perfect); but on the other hand, a better hope is introduced, through which we draw near to God. Hebrews 7:19 (ESV)
We have far better and surer hope in Jesus as our eternal high priest unlike the temp priesthood of men.
This makes Jesus the guarantor of a better covenant. Hebrews 7:22 (ESV)
Our eternal security is very secure because the one giving the guarantee is Jesus himself
For it was indeed fitting that we should have such a high priest, holy, innocent, unstained, separated from sinners, and exalted above the heavens. Hebrews 7:26 (ESV)
5 distinctives of Christ’s priesthood