The thought “this is how we know” occurs eight times in 1 John. The translation of Scripture I normally use is the 1984 edition of the New International Version (NIV84). It may be worded differently in the translation you use, but this recurring phrase is in the following passages.

1 John 2:5 But if anyone obeys his word, God’s love is truly made complete in him. This is how we know we are in him:

1 John 2:18 Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour.

1 John 3:10 This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not a child of God; nor is anyone who does not love his brother.

1 John 3:16 This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers.

1 John 3:19 This then is how we know that we belong to the truth, and how we set our hearts at rest in his presence

1 John 3:24 Those who obey his commands live in him, and he in them. And this is how we know that he lives in us: We know it by the Spirit he gave us.

1 John 4:6 We are from God, and whoever knows God listens to us; but whoever is not from God does not listen to us. This is how we recognize the Spirit of truth and the spirit of falsehood.

1 John 5:2 This is how we know that we love the children of God: by loving God and carrying out his commands.

John uses this phrase to show his brothers and sisters in Christ that there is reason for certainty, confidence and conviction. We have evidence, we have proof. We just need to see things for what they are. People reveal themselves by their actions, good or bad. In His Sermon on the Mount, our Lord said , “By their fruit you will know them…” (Matthew 7).

In the same way, we know God by His actions. His Spirit abides in those who put their faith in Him. Our efforts to live according to His will show us to be His children. And we know His love because we have seen it in Jesus laying down His life for us.

One way “this is how I know” is reinforced for me is in the songs and hymns of the church. This is one I learned in Kindergarten or First Grade back at St. Paul/First English Lutheran School in New Orleans, and it is still a favorite of mine.

There is a green hill far away, Without a city wall,
Where the dear Lord was crucified, Who died to save us all.

We may not know, we cannot tell, What pains He had to bear,
But we believe it was for us He hung and suffered there.

He died that we might be forgiven, He died to make us good,
That we might go at last to heaven, Saved by His precious blood.

There was no other good enough To pay the price of sin,
He only could unlock the gate Of heaven and let us in.

Oh, dearly, dearly has He loved! And we must love Him too
And trust in His redeeming blood, And try His works to do.

(The Children’s Hymnal #43, Concordia Publishing House, 1955)