Charles Spurgeon Commentary 1 John 2:23-28

"Whosoever denieth the Son, the same hath not the Father: he that confesseth the Son hath the Father also. As for you, let that abide in you which ye heard from the beginning. If that which ye heard from the beginning abide in you, ye also shall abide in the Son, and in the Father. And this is the promise which he promised us, [even] the life eternal. These things have I written unto you concerning them that would lead you astray. And as for you, the anointing which ye received of him abideth in you, and ye need not that any one teach you; but as his anointing teacheth you; concerning all things, and is true, and is no lie, and even as it taught you, ye abide in him. And now, [my] little children, abide in him; that, if he shall be manifested, we may have boldness, and not be ashamed before him at his coming." — 1 John 2:23-28 (ASV)

[But] he that acknowledges the Son has the Father also.

Let that therefore abide in you, which you have heard from the beginning. If that which you have heard from the beginning shall remain in you, you also shall continue in the Son, and in the Father.

And that is the promise that he has promised us, even eternal life.

These things I have written to you concerning them that seduce you. But the anointing which you have received from him abides in you, and you need not that any man teach you: but as the same anointing teaches you of all things, and is truth, and is no lie, and even as it has taught you, we shall abide in him. And now, little children, abide in him; –

That which is the subject of promise is also the subject of precept; and the precepts of the gospel are given to Christians because, in this way, God keeps his own promise, and so leads me to obey his precepts.