The structure of this paragraph is as follows:
Verse 7 contains the main point of the paragraph expressed in the exhortation “let us love one another. This is the first open exhortation to love one another in the letter.
In vv. 7-8, John gives two grounds or reasons for the command to love one another. The first is love has its source in God. The second is that “whoever loves has been born of God and knows God.” Two things are said to be true about Christians who practice love: 1) they have been born of God, and 2) they know God.
In verse 8, John reverses what he said in verse 7 by placing it in the negative for emphasis. This functions as the antithesis of what is stated in verse 7b.
Vv. 9-10 demonstrate the love of God in the fact that He sent Jesus to die on the cross for our sins. Each verse provides a reason for the command in verse 7. There is little difference in the content of vv. 9-10. Verse 10 further amplifies the statement in v. 9. In verse 9, because of God’s love, Jesus is sent into the world that we might live through him. In verse 10, the means by which we may live through him is further amplified in the fact that Christ’s death was a “propitiation;” an “atoning sacrifice” for sin.
Verse 11 concludes the paragraph by repeating the exhortation in v. 7, but in a mitigated fashion. In v. 7 it is “Let us love one another;” in v. 11 it is “we ought to love one another.”
Basically, the structure of the paragraph contains a single imperative expressed twice in vv. 7 and 11, with two grounds or reasons given for the command to love.
I. Practice Love – (7a)
A. Love is personified in God Himself – (7b–8).
1) Love is evidence of the new birth and knowledge of God
B. Love is proven by God sending Jesus to die for our sins – (9–10).
II. Therefore, practice love – (11)