Heb 6:1
6:1 Therefore leaving the {a} principles of the doctrine of
    Christ, let us go on unto perfection; {1} not laying again
    the foundation of repentance from dead works, and of faith
    toward God,

    (a) The first principle of Christian religion, which we call
        the catechism.
 (1) Certain principles of a catechism, which comprehend the sum
     of the doctrine of the gospel, were given in few words and
     briefly to the poor and unlearned, that is, the profession
     of repentance and faith in God. The articles of this
     doctrine were required from those who were not yet members
     of the Church on the days appointed for their baptism.  Of
     those articles, two are by name recited: the resurrection
     of the dead, and eternal judgment. (Ed.)

Heb 6:4
6:4 {2} For [it is] {b} impossible for those who were once
    enlightened, and have {c} tasted of the heavenly gift, and
    were made partakers of the Holy Ghost,

 (2) He adds a vehemency to his exhortation, and a sharp
     threatening of the certain destruction that will come to
     them who fall away from God and his religion.
    (b) He speaks of a general backsliding and those who fall
        away from the faith completely, not of sins committed
        through the weakness of a man against the first and the
        second table of the law.
    (c) We must note the force of this word, for it is one thing
        to believe as Lydia did, whose heart God opened in
        Ac 16:13 and another thing to have some taste.

Heb 6:6
6:6 If they shall fall away, to renew them again unto
    repentance; seeing they {d} crucify to themselves the Son of
    God afresh, and put [him] to an open shame.

    (d) As men that hate Christ, and as though they crucified
        him again, making a mockery of him to all the world, to
        their own destruction, as Julian the Apostate or
        backslider did.

Heb 6:7
6:7 {3} For the earth which drinketh in the rain that cometh oft
    upon it, and bringeth forth herbs meet for them by whom it
    is dressed, receiveth blessing from God:

 (3) He lays out the former threatening with a comparison.

Heb 6:9
6:9 {4} But, beloved, we are persuaded better things of you, and
    things that accompany salvation, though we thus speak.

 (4) He moderates and calms all that sharpness, expecting better
     things of those to whom he writes.

Heb 6:10
6:10 {5} 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.

 (5) He praises them for their charity, by this encouraging them
     to go forward, and to hold out to the end.

Heb 6:12
6:12 {6} That ye be not slothful, but followers of them who
     through faith and patience inherit the promises.

 (6) He shows in these verses that they need to go forward
     constantly, for their own good: that is, of charity, and
     patience; and lest any man should object and say that these
     things are impossible to do, he asks them to consider the
     examples of their ancestors and to follow them.

Heb 6:13
6:13 {7} For when God made promise to Abraham, because he could
     swear by no greater, he sware by himself,

 (7) Another encouragement, to push them onward because the
     hope of the inheritance is certain, if we continue to the
     end, for God has not only promised it, but also promised it
     with an oath.

Heb 6:14
6:14 Saying, Surely {e} blessing I will bless thee, and
     multiplying I will multiply thee.

     (e) I will heap many benefits on you.

Heb 6:17
6:17 Wherein God, willing more {f} abundantly to shew unto the
     heirs of promise the immutability of his counsel, confirmed
     [it] by an oath:

     (f) More than was needed, were it not for the wickedness of
         men who do not believe God, even though he swears.

Heb 6:19
6:19 {8} Which [hope] we have as an anchor of the soul, both
     sure and stedfast, and which entereth into that within the
     veil;

 (8) He compares hope to an anchor because in the same way that
     an anchor when cast into the bottom of the sea secures the
     whole ship, so hope also enters even into the very secret
     places of heaven. He makes mention of the sanctuary,
     alluding to the old tabernacle and by this returns to the
     comparison of the priesthood of Christ with the Levitical
     priesthood.

Heb 6:20
6:20 {9} Whither the forerunner is for us entered, [even] Jesus,
     made an high priest for ever after the order of
     Melchisedec.

 (9) He repeats David's words, in which all those comparisons
     that he mentioned before are signified, as he declares in
     all the next chapter.