A bevy of Johannine citations! And a smattering of themes and ideas. But as someone born and raised in the "Show Me" state, please go easy on Thomas this weekend...
1 John 1:1-2:2
...but if we walk in the light as he himself is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin.
-- 1 John 1:7
Verse 7 (of chapter 1) is cited three times in Formula of Concord, Solid Declaration. First, verse 7 is quoted in Article 3: Righteousness (SD 3.57) along with a few other quotes to show that Jesus' own obedience to the Father's will is what is reckoned to us as righteousness. Christ's faith is what saves us.
The second citation is a quote in Article 8: Person of Christ (SD 8.59) where this verse is used as the third "strong, irrefutable" argument (SD 8.56) that the two natures of Christ are not simply a semantic trick. This verse shows us the humanity of Jesus in that the emphasis is on Jesus' blood, which is not about Jesus' merit, worthiness, or work (which does matter, but is from his divine nature) but is about his humanity. Jesus' blood cleanses us, and this cannot be abstracted into something other than the blood of one human offered as the only acceptable sacrifice.
This verse is finally cited in Article 11: Election (SD 11.28) along with 2:2 below to show with several other passages that Jesus' sacrifice is for all. This verse is only the first part of that argument, and we really need 2:2 to complete it.
If we say that we have no sin, we deceive ourselves, and the truth is not in us.
-- 1 John 1:8
Verse 8 (also of chapter 1) is quoted in Apology of the Augsburg Confession, Article 4: Justification (AP 4.181ish) along with many other biblical quotes to make clear that we cannot by our own effort or work save ourselves for even our works are sinful.
Verse 8 is also quoted in Smalcald Articles, Part 3, Article 3: Concerning Repentance (SA 3.3.45) in a later addition to the Articles where Luther makes clear that when faithful people sin, the Holy Spirit leaves them, and therefore so does their faith. This verse is one of two citations from 1 John that Luther cites to makes this point.
My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous;
-- 1 John 2:1
The second part of verse 1 of chapter 2 is quoted in The Augsburg Confession, Article 21: The Cult of the Saints (AC 21.4) at the end to make clear that while we should study and learn from the lives of the saints, we shouldn't trouble them now that their dead with our prayers because Jesus himself will intercede for us with the Father.
and he is the atoning sacrifice for our sins, and not for ours only but also for the sins of the whole world.
-- 1 John 2:2
Verse 2 of chapter 2 is cited in a footnote to Apology of the Augsburg Confession, Article 4: Justification (AP 4.40, n. 73) to note that Melanchthon's use of the word "propitiator" is a direct reference to this verse and Romans 3:25 lifting up the idea of Jesus as the atoning sacrifice.
As noted above, this verse is also cited in Formula of Concord, Solid Declaration, Article 11: Election (SD 11.28) to show with several other passages that Jesus' sacrifice is for all.
Jesus said to them again, “Peace be with you. As the Father has sent me, so I send you.” When he had said this, he breathed on them and said to them, “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven them; if you retain the sins of any, they are retained.”
--John 20:21-23, NRSV
Verses 21 thru 23 are quoted in The Augsburg Confession, Article 28: Concerning the Power of Bishops/Concerning the Church's Power (AC 28.6) to clarify the teaching of the reformers about what said "power" is--namely "to preach the gospel, to forgive or retain sin, and to administer and distribute the sacraments" (AC 28.5).
Verse 21 is quoted twice in Treatise on the Power and Primacy of the Pope (Tr 9, 31) to make two different points. The first citation is to show that Jesus did not create a hierarchy among the apostles, so the office of Pope does not have any ordained primacy. The second citation, with several other scriptural references, makes the argument that those who hold positions of authority in the church do not have God's authorization to civil authority and enforcement.
Verse 23 comes up in a smattering of places. First in a footnote in Smalcald Articles, Part 3, Article 7 (SA 3.7.1, n. 140) showing that Jesus gave the church authority to bind and loose sins. This verse is quoted in Treatise on the Power and Primacy of the Pope (Tr 23) to show that Jesus gave all the apostles authority to bind and loose sins. Finally, this verse is cited in a footnote in Small Catechism, Baptism, Short Order of Confession (SC Baptism.29, n. 95) as a scriptural citation for the command of Jesus by which forgiveness is pronounced.
Jesus gives the Church authority to proclaim the gospel to all people and forgive sins or not. Probably not the kind of authority we think of as useful. And the authority to bind sins is kind of dangerous given the Lord's Prayer reminder that we ask God to "forgive us our sins as we forgive those who sin against us." On this Second Sunday of Easter, when the apostle Thomas is much defamed as a doubter, it is helpful to remember that without Jesus' sacrifice and the presence of the Holy Spirit, all of us are faithless.