Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God,
Therefore leaving the principles of the doctrine of Christ — That is, saying no more of them for the present.
Let us go on to perfection; not laying again the foundation of repentance from dead works — From open sins, the very first thing to be insisted on.
And faith in God — The very next point. So St. Paul in his very first sermon at Lystra, Acts 14:15, "Turn from those vanities unto the living God." And when they believed, they were to be baptized with the baptism, not of the Jews, or of John, but of Christ. The next thing was, to lay hands upon them, that they might receive the Holy Ghost: after which they were more fully instructed, touching the resurrection, and the general judgment; called eternal, because the sentence then pronounced is irreversible, and the effects of it remain for ever.
 And this will we do, if God permit.
And this we will do — We will go on to perfection; and so much the more diligently, because,
 For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
It is impossible for those who were once enlightened — With the light of the glorious love of God in Christ.
And have tasted the heavenly gift — Remission of sins, sweeter than honey and the honeycomb.
And been made partakers of the Holy Ghost — Of the witness and the fruit of he Spirit.
 And have tasted the good word of God, and the powers of the world to come,
And have tasted the good word of God — Have had a relish for, and a delight in it.
And the powers of the world to come — Which every one tastes, who has an hope full of immortality. Every child that is naturally born, first sees the light, then receives and tastes proper nourishment, and partakes of the things of this world. In like manner, the apostle, comparing spiritual with natural things, speaks of one born of the Spirit, as seeing the light, tasting the sweetness, and partaking of the things "of the world to come."
 If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
And have fallen away — Here is not a supposition, but a plain relation of fact. The apostle here describes the case of those who have cast away both the power and the form of godliness; who have lost both their faith, hope, and love, Hebrews 10:26. Of these wilful total apostates he declares, it is impossible to renew them again to repentance. (though they were renewed once,) either to the foundation, or anything built thereon.
Seeing they crucify the Son of God afresh — They use him with the utmost indignity.
And put him to an open shame — Causing his glorious name to be blasphemed.
 But that which beareth thorns and briers is rejected, and is nigh unto cursing; whose end is to be burned.
That which beareth thorns and briers — Only or chiefly.
Is rejected — No more labour is bestowed upon it.
Whose end is to be burned — As Jerusalem was shortly after.
 But, beloved, we are persuaded better things of you, and things that accompany salvation, though we thus speak.
But, beloved — in this one place he calls them so. he never uses this appellation, but in exhorting.
We are persuaded of you things that accompany salvation — We are persuaded you are now saved from your sins; and that ye have that faith, love, and holiness, which lead to final salvation.
Though we thus speak — To warn you, lest you should fall from your present steadfastness.
 For God is not unrighteous to forget your work and labour of love, which ye have shewed toward his name, in that ye have ministered to the saints, and do minister.
For — Ye give plain proof of your faith and love, which the righteous God will surely reward.
 And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end:
But we desire you may show the same diligence unto the end — And therefore we thus speak.
To the full assurance of hope — Which you cannot expect, if you abate your diligence. The full assurance of faith relates to present pardon; the full assurance of hope, to future glory. The former is the highest degree of divine evidence that God is reconciled to me in the Son of his love; the latter is the same degree of divine evidence (wrought in the soul by the same immediate inspiration of the Holy Ghost) of persevering grace, and of eternal glory. So much, and no more, as faith every moment "beholds with open face," so much does hope see to all eternity But this assurance of faith and hope is not an opinion, not a bare construction of scripture, but is given immediately by the power of the Holy Ghost; and what none can have for another, but for himself only.
 That ye be not slothful, but followers of them who through faith and patience inherit the promises.
Inherited the promises — The promised rest; paradise.
 For when God made promise to Abraham, because he could swear by no greater, he sware by himself,
For — Ye have abundant encouragement, seeing no stronger promise could be made than that great promise which God made to Abraham, and in him to us.
 Saying, Surely blessing I will bless thee, and multiplying I will multiply thee.
 And so, after he had patiently endured, he obtained the promise.
After he had waited — Thirty years.
He obtained the promise — Isaac, the pledge of all the promises.
 For men verily swear by the greater: and an oath for confirmation is to them an end of all strife.
Men generally swear by him who is infinitely greater than themselves, and an oath for confirmation, to confirm what is promised or asserted, usually puts an end to all contradiction. This shows that an oath taken in a religious manner is lawful even under the gospel: otherwise the apostle would never have mentioned it with so much honour, as a proper means to confirm the truth
 Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath:
God interposed by an oath — Amazing condescension! He who is greatest of all acts as if he were a middle person; as if while he swears, he were less than himself, by whom he swears! Thou that hearest the promise, dost thou not yet believe?
 That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us:
That by two unchangeable things — His promise and his oath, in either, much more in both of which, it was impossible for God to lie, we might have strong consolation - Swallowing up all doubt and fear.
Who have fled — After having been tossed by many storms.
To lay hold on the hope set before us — On Christ, the object of our hope, and the glory we hope for through him.
 Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil;
Which hope in Christ we have as an anchor of the soul — Entering into heaven itself, and fixed there.
Within the veil — Thus he slides back to the priesthood of Christ.
 Whither the forerunner is for us entered, even Jesus, made an high priest for ever after the order of Melchisedec.
A forerunner uses to be less in dignity than those that are to follow him. But it is not so here; for Christ who is gone before us is infinitely superior to us. What an honour is it to believers, to have so glorious a forerunner, now appearing in the presence of God for them.