1. We have the Holy Spirit but Scripture speaks to the authority of the Church for unity of faith.
Matt 18:15 “If your brother sins [against you], go and tell him his fault between you and him alone. If he listens to you, you have won over your brother. 16 If he does not listen, take one or two others along with you, so that ‘every fact may be established on the testimony of two or three witnesses.’ 17 If he refuses to listen to them, tell the church. If he refuses to listen even to the church, then treat him as you would a Gentile or a tax collector.2. We are individuals but we are supposed to be united in faith. Look around and see the disunity brought by private interpretation. The devil uses the fallibility of the individual to divide our unity. We have the indwelling of the Spirit but looking at the world can we truly say that Christians are united in that same Spirit?1 Tim 3:15 But if I should be delayed, you should know how to behave in the household of God, which is the church of the living God, the pillar and foundation of truth.
3. New Testament Scripture came from the Church, not the other way around. Jesus founded His Church upon the Apostles (Matt 16:18) and this Church is shown clearly throughout the New Testament as they wrote to the far-flung congregations for reproof and encouragement. There is no basis for the Epistles except that there was a central authority in the Church.
4. If you haven't noticed, we are having issues with the Church hierarchy and it's been a big problem since Vatican II. If you think Christianity will flourish in the world without the Catholic Church, you haven't been paying attention. We are praying and seeking correction from our Bridegroom. The Church is only holy in Her communion with Him.
Sigh.
The Church has authority to discipline members. That covers the two passages you mention. Totally agree and have taken part in it in churches.
Instead of looking at the “disunity brought by private interpretation”, look at the heresy brought about by the political rulers of the Roman Catholic Church, to include replacing the Word of God with their man-made rules - from “priests” to “Purgatory”.
We need a standard and that standard is the Word of God. Not the Roman Catholic Bishops and Pope, most of whom have been non-Christians.
The churches ACCEPTED the New Testament but did not create it. NO church or Bishop directed its writing. The churches role - and not just the ROMAN church - was to reject phony additional scriptures - and the Roman Catholic Church failed to do that in spite of Jerome’s urging.
“If you think Christianity will flourish in the world without the Catholic Church, you haven’t been paying attention”
If you think the Catholic Church is seriously “Christian”, you haven’t been paying attention!