Okay
Νῦν χαί.ρω ἐν τοῖς πα.θή.μα.σιν ὑ.πὲρ ὑ.μῶν, καὶ ἀν.τα.ναπ.λη.ρῶ τὰ ὑσ.τε.ρή.μα.τα τῶν θλίψ.ε.ων τοῦ Χρισ.τοῦ ἐν τῇ σαρ.κί μου ὑ.πὲρ τοῦ σώ.μα.τος αὐ.τοῦ, ὅ ἐσ.τιν ἡ ἐκ.κλη.σί.α,
Nun [3568 now, just now, at the present time] chairō [5463 to rejoice, to be glad] en [1722 in, a being or remaining within, with the primary idea of rest in any place or thing. Of place, in, within, among. Of time, on, upon] ho [3588 his - the definite article, the; here, the Genitive, τοῦ (tou) of the (one referred to, that is to say God) hence, his] pathēma [3804 affliction, suffering] huper [5228 on behalf of another, for] humeis [5210 ye -(nominative plural ο (o 3588)f σύ (su 4771) thou) ye, you] kai [2532 and, also, even, a conjunction] antanaplēroō [466 to fill up] ho [his again: see above 3588] husterēma [5303 that which comes short, that which is wanting, lack, deficiency, want] ho thlipsis [2347 tribulation, pressure, affliction] ho Christos [5547 anointed one, Messiah] en ho sarx [4561 - flesh; then, corporeity according to its material side (σῶμα (sōma 4983) being the organic whole, the body, and therefore is to be distinguished from it); then, the outward form of human nature, and therefore human nature in its embodiment. As used by St. Paul, all that is peculiar to human nature in its corporeal embodiment is said to belong to it; and hence, he uses it as the distinct antithesis to πνεῦμα (pneuma 4151) (spirit)] huper [5228 - over and separate from; here only with Genitive on behalf of, as though bending over to protect] ho sōma [4983 body - the body as a whole whether man or animals] autos [846 - very, self, joined with each of the persons, with the third person, not simply he, but he himself, he and no other. Always emphatic] hos [3739 whosoever, whomsoever, who, which] eimi [1510 is] ho ekklēsia [1577 church -the common term for a meeting of the ἔκκλητοι (ekklētoi) (those summoned) to discuss the affairs of a Free State; the body of citizens summoned together by a herald (κῆρυξ (kērux 2783)). The Greek translation of the Old Test. transfer the term to the assembly of the people of Israel, whether summoned or met for a definite purpose (1Ki 8:65), or considered as the representative of the entire nation. In NT it denotes the redeemed community in its two-fold aspect. (i) The entire community of all who are called by and to Christ out of the world, the Church universal (ii) every Church in which the character of the Church as a whole is seen in miniature. The summoning is expressed by the latter part of the word (καλεῖν (kalein)), and out of by the first part (ἐκ (ek 1537))].
KJV - Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body's sake, which is the church:
NASV - Now I rejoice in my sufferings for your sake, and in my flesh I do my share on behalf of His body, which is the church, in filling up what is lacking in Christ's afflictions.
ESV - Now I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ’s afflictions for the sake of his body, that is, the church,
Personally what I'm seeing from the GREEK text here is that the church is a body of believers summoned together, who will suffer affliction and trials which is a reason to rejoice. Again, not a name over the door. You interpret this as the Roman Catholic Church, but the text doesn't say that. The text says those who are redeemed constitute the church.
"This reconciliation by Christ of Jews and Gentiles to God in one body is a mystery revealed only in Christ. Paul rejoiced that he was able to suffer for them what was still lacking in regard to Christ's afflictions. By this he did not mean that Christ's suffering on the cross was insufficient (cf. Rom. 3:21-26; Heb. 10:10-14). He was speaking not of salvation but of service. Christ's suffering alone procures salvation (I Peter 1:11; 5:1; Heb. 2:9). But it is a believer's privilege to suffer for Christ (2 Tim. 3:11; I Peter 3:13-14; 5:9; Heb. 10:32). The word 'affliction' (thlipsis) - never used in the New Testament of Christ's death - means 'distress', 'pressure', or 'trouble' (which Paul had plenty of; 2 Cor. 11:23-29). Ordinarily it refers to trials in life, not the pains of death. Christ does indeed continue to suffer when Christians suffer for Him....since the church is Christ's body, He is affected when it is affected. For the sake of Christ's body Paul willingly suffered (Phil. 1:29)." (The Bible Knowledge Commentary, Walvoord, Zuck, Chariot Victor Publishing, c1983; p. 675).
It is remarkable that Paul, who writes so beautifully and compellingly about the sufficiency of Christ's sacrifice would later make a statement like this.
I like to say that in Faith in which "One" (as in "one God") doesn't mean what the average person thinks it means, "Complete" may have some surprises as well.
Now I just don't think name calling and perseveration leads to any good thing. So if you want to fight about religion, I am NOT your boy. If you want to talk about it as brethren seeking some common ground, that's another story.