How can you fail to see (unless you do not want to) that the issue is not the right to exercise spiritual discipline, but the basis and means by which it is done?
In the NT church the only means of discipline, outside the passive means of disfellowship, was by spiritual means, not the use of the sword of men against theological dissenters.
This meant that leadership had to rely upon God to confirm that their judgment was right by Him executing the judgment, versus earthly physical punishment of the disobedient, which is what Rome ordained and promoted, and early Prots had to unlearn. Meanwhile the just use of the sword of men against immoral acts by the State was sanctioned.
For the kingdom of God is not in word, but in power. What will ye? shall I come unto you with a rod, or in love, and in the spirit of meekness? (1 Corinthians 4:20-21)
In the name of our Lord Jesus Christ, when ye are gathered together, and my spirit, with the power of our Lord Jesus Christ, To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus. (1 Corinthians 5:4-5)
But I beseech you, that I may not be bold when I am present with that confidence, wherewith I think to be bold against some, which think of us as if we walked according to the flesh. For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) (2 Corinthians 10:2-4)
Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence. (John 18:36)
For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. (Ephesians 6:12)
Of whom is Hymenaeus and Alexander; whom I have delivered unto Satan, that they may learn not to blaspheme. (1 Timothy 1:20)
But as with Islam, Mormons, Jim Jones,m etc, whenever man and or another revelation is made higher than Scripture, then both the bodies and souls of men are in danger of them.
I was wondering how those who believe Paul (and, by extension, the church) was pronouncing an actual death sentence on this member who was guilty of a grave sin can explain how his spirit/soul is saved in the day of the Lord? How does killing a heretic ensure his salvation?