John the Apostle
1 John 2:25ESV·traditional attribution

And this is the promise that he made to us—eternal life.

John Calvin Reformed @genevareformer

In the last place, he reminds us that it is real happiness when God dwells in us. The words he uses are ambiguous. They may be rendered, “This is the promise which he has promised to us, even eternal life.” This, which is our version, is, no doubt, the best construction.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. The apostle encourages the disciples (to whom he writes) in these dangerous times, in this hour of seducers; he encourages them in the assurance of their stability in this day of apostasy: But you have an unction from the Holy One, and you know all things. We see, 1. The blessing wherewith they were enriched - an unguent from heaven: You have an unction.

Commenting on 1 John 2:20-27

John Gill Reformed Baptist @doctorgill

And this is the promise that he hath promised us,.... Either God the Father, who is that God that cannot lie, who in the covenant of his grace, before the world began, made this promise unto his people, even eternal life; which promise, with all others, was put into the hands of Christ, where, with them, it is yea and amen; and also the thing...