Note from Bengel on Rom. i. 4.
'_According to the Spirit of Holiness._ The word _hagios_, holy, when
God is spoken of, not only denotes the blameless rectitude in action,
but the very Godhead, or to speak more properly, the _divinity_, or
excellence of the Divine nature. Hence _hagiosune_ (the word here used)
has a kind of middle sense between _hagiotes_, holiness, and
_hagiasmos_, sanctification. Comp. Heb. xii. 10 (_hagiotes_ or
holiness), v. 14 (_hagiasmos_ or sanctification). So that there are, as
it were, three degrees: _sanctification_, _sanctity of life_,
_holiness_. Holiness is ascribed to the Father, the Son, and the Holy
Ghost. And since here the Holy Spirit is not mentioned, but the spirit
of holiness (prop. sanctity, _hagiosune_), we must further inquire what
this remarkable expression denotes. The name spirit is expressly and
very frequently given to the Holy Spirit; but God is also called a
spirit; and the Lord Jesus Christ is called a spirit, but in contrast to
the latter. (2 Cor. iii. 17.) With this we must compare the fact that,
as in this passage, so often the antithesis of flesh and spirit is found
where Christ is spoken of. (1 Tim. iii. 16; 1 Pet. iii. 18.) In these
passages the Spirit is applied to whatever belongs to Christ (apart from
the flesh, although this was pure and holy, and above the flesh),
through His generation of the Father, who sanctified Him: in short, His
Godhead itself. For here, _flesh_ and _spirit_, and chap. ix. 5, _flesh_
and _Godhead_, stand in mutual contrast. This spirit is here called not
the spirit of holiness, the usual title of the Holy Spirit; but it is
called in this passage _the spirit of sanctity_, to suggest at once the
efficacy of that holiness or divinity, which led of necessity to the
Saviour's resurrection, and by which it was most forcibly illustrated,
and also that spiritual and holy, or Divine power of Jesus who has been
glorified and yet retained a spiritual body. Before the resurrection the
spirit was concealed under the flesh; after the resurrection the spirit
of sanctity concealed the flesh. In reference to the former, He was wont
to call Himself the Son of man; in reference to the latter, He is known
as the Son of God.'