The first epistle of John is often said to have a comparatively impoverished vocabulary compared to the gospel. It is also said to have ‘worked to death’ a very few select themes.

In a blog-length letter—a little under 2200 words—John used ‘eido’, to know the truth, seventeen times. Of course ensuring such an important word appears this exact number of times in such a comparatively short letter virtually guarantees this theme will appear to be over-emphasised.

1. But you have an anointing from the Holy One, and all of you know the truth. 1 John 2:20 NIV
2. I do not write to you because you do not know the truth… 1 John 2:21 NIV
3. …but because you do know it and because no lie comes from the truth. 1 John 2:21 NIV
4. If you know that he is righteous… 1 John 2:29 NIV
5. …you know that everyone who does what is right has been born of him. 1 John 2:29 NIV
6. How great is the love the Father has lavished on us, that we should be called children of God! And that is what we are! The reason the world does not know us is that… 1 John 3:1 NIV
7. …it did not know him. 1 John 3:1 NIV
8. But you know that he appeared so that he might take away our sins.  1 John 3:5 NIV
9. We know that we have passed from death to life, because we love our brothers. Anyone who does not love remains in death. 1 John 3:14 NIV
10. Anyone who hates his brother is a murderer, and you know that no murderer has eternal life in him. 1 John 3:15 NIV
11. I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.  1 John 5:13  NIV
12. And if we know that he hears us—whatever we ask… 1 John 5:15 NIV
13. …we know that we have what we asked of him. 1 John 5:15 NIV
14. We know that anyone born of God does not continue to sin; the one who was born of God keeps him safe, and the evil one cannot harm him. 1 John 5:18 NIV
15. We know that we are children of God, and that the whole world is under the control of the evil one. 1 John 5:19 NIV
16. We know also that the Son of God has come and has given us understanding… 1 John 5:20 NIV
17. …so that we may know him who is true. 1 John 5:20 NIV