Actually it was written to the church generally, so it has more to do with us than a lot of books.
No, it was written to those who had an unction from the Holy one and need not any man teach them (1 John 2:20 KJV, 1 John 2:27 KJV) and in a tribulation context looking forward to the fountain being opened unto them for sin and uncleanness. That is who and what the passage is about entirely!
1 John 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
1 John 1:9 means exactly what it says, as it says it and to whom it says it. It is just not written to me for my obedience, nor anyone else in the dispensation of the grace of God. It's not our good news.
1 John 1:9 will happen in that day when a fountain is opened to the house of David and to the inhabitants of Jerusalem for sin and uncleanness.
Zechariah 13:1 In that day there shall be a fountain opened to the house of David and to the inhabitants of Jerusalem for sin and for uncleanness.
"That day" would be what many refer to as the second coming of the Lord (the Body of Christ has already been caught up to meet the Lord in the air 1 Thessalonians 4:16-18).
This is in one accord with what Peter preached in Acts 3:
Acts 3:19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; 20 And he shall send Jesus Christ, which before was preached unto you: 21 Whom the heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the world began.
Act 3:19-21 has nothing to do with the Body of Christ. Israel looks forward to the blotting out of their sins. That's what it says. For that is God's covenant unto them when He shall take away their sins.
Romans 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. 26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob: 27 For this is my covenant unto them, when I shall take away their sins.
Israel looks forward to their sins being blotted out while we in the Body of Christ look back to the cross. We have already received the atonement.
Romans 5:11 And not only so, but we also joy in God through our Lord Jesus Christ, by whom we have now received the atonement.
Galatians, however, wasn't written to us at all. Paul told us who his books were for.
Galatians 1:1-2
Paul, an apostle, (not of men, neither by man, but by Jesus Christ, and God the Father, who raised him from the dead) And all the brethren which are with me, unto the churches of Galatia:
Sent from my iPhone using
TOL
Although the Galatians were not the same kind of Gentiles as we in time past, Paul is the apostle of the Gentiles (Romans 11:13 KJV) writing to Gentiles who had received the gospel that Paul preached (Galatians 1:8-12 KJV)! They are of those to whom Paul was first sent/ called into the grace of Christ (Galatians 1:6 KJV) and of those who first trusted in Christ (Ephesians 1:12 KJV). Romans through Philemon is the form of sound words written directly to us (2 Timothy 1:13 KJV)!