Matthew Poole and continuators on 1 John 2:9

9 He that saith he is in the light , and hateth his brother, is in darkness until now .

To be in the Light, signifies to be under the transforming governing Power of it, as the Phrases import of being in the Flesh, and in the Spirit, Rom. 8.9. being expounded by walking after the Flesh, and after the Spirit, v. 1. He therefore that hateth his Brother, a thing so contrary to the Design of the Gospel, whatever he pretends, is still in Darkness,

under the Power of the unregenerate Principle of impure and malignant Darkness. The Gospel hath done him no good, is to him but an impotent, and ineffectual Light, in the midst whereof, by stiff winking, and an obstinate Resistance, and Exclusion of that pure and holy Light, he creates to himself a dark and an hellish Night.

Marginal references: 1 Cor. 13.2. 2 Pet. 1.9. Chap. 3.14, 15.