Apparently, O. Winslow was dispensationally thinking in regard to the indwelling of the Holy Spirit. He writes:

“Speaking of the legal dispensation, with which the
temple prepared by David and built by Solomon was designed
to harmonise, the apostle argues that it possessed no glory in
comparison with the Gospel economy. And why? Because
there was less of the Spirit in the former than in the present
dispensation. It was the enlarged manifestation of the Spirit,
especially His indwelling of the saints, which constituted the
peculiar and far-surpassing glory of the new economy”

I believe he is confusing the amplification of the HS, i.e. Pneuma Hagion at Pentecost, i.e. the paraklete, with how the converted are ‘sealed’ in the HS upon belief. To deny this, is a direct charge on total depravity; to not have the indwelling spirit of God is to immediately apostatize from the faith.

He goes on to say:

“The superior glory of the new dispensation then is that it is more spiritual: there is a more enlarged and rich effusion of the quickening, sanctifying and sealing influences of the Holy Spirit; there is more of Christ, more of the holy liberty of adoption, a more simple, spiritual and child-like approach to God. But especially does the indwelling of the Spirit in the saints form a distinguished feature of the new economy.”

Winslow goes on to admit:

“We even dare assert that the conversion
of a soul, the sustaining of the work wrought in that soul, the keeping of the believer through a long life of holy, upright and close walk with God, and the bringing of him safe to eternal happiness, are greater displays of the mighty power of God and more glorify Him than the creation of ten thousand worlds like ours.The Spirit dwells in the believer as the everliving Spirit of all grace and comfort. All that is really holy and gracious in a child of God is found in the work of the indwelling Spirit. All the holy breathings and desires of the soul, all the longings for God and for conformity to His w i l l and image, all that is lovely and like Jesus in the saint, are the result of this gracious act of the eternal Spirit. The Lord Jesus Himself would direct us to this truth. ”

On one hand, he admits that the believer could not have any hope outside of what the HS accomplishes with this filling, and on the other, shoots himself in the foot as he says that the OT saint does not have this indwelling.

“Here is a gracious truth. The Spirit in every believer is a deep and living well of all spiritual blessings. He dwells in the soul ” not like a stagnant pool, but like an ever-living fountain that plays at all seasons of the year, in heat and cold, and in all external circumstances of weather, whether foul or fair, wet or dry.” Nature could not produce that which the indwelling Spirit accomplishes in the saints of God. The hungering and the thirsting for righteousness, the rising of the heart in filial love to God, the sweet submission to His sovereign will, the longing for more knowledge of Christ, the constant struggling with the law of sin, the mourning over the indwelling principle of sin; all this is above and far beyond nature. It is the fruit, the precious fruit, of the indwelling Spirit.”

Apparently, the OT saint was not as depraved as the NT saint as he didn’t need the indwelling spirit to persevere