I apologize for not posting this sooner.
I find it hard for one to not abandon or remove himself from the Body of Christ while removing himself from unity with Christ as Pope Eugenius explains below.
*Pope Eugenius IV, Cantate Domino (1441): “The most Holy Roman Church firmly believes, professes and preaches that none of those existing outside the Catholic Church, not only pagans, but also Jews and heretics and schismatics, can have a share in life eternal; but that they will go into the “eternal fire which was prepared for the devil and his angels” (Matthew 25:41), unless before death they are joined with Her; and that so important is the unity of this ecclesiastical body that only those remaining within this unity can profit by the sacraments of the Church unto salvation, and they alone can receive an eternal recompense for their fasts, their almsgivings, their other works of Christian piety and the duties of a Christian soldier. No one, let his almsgiving be as great as it may, no one, even if he pour out his blood for the Name of Christ, can be saved, unless he remain within the bosom and the unity of the Catholic Church.”
Pope Innocentius III, Profession of Faith: “With our hearts we believe and with our lips we confess but one Church, not that of the heretics, but the Holy Roman Catholic and Apostolic Church, outside which we believe that no one is saved”
Pope Gregorius XVI, Summo Jugiter Studio, May 27, 1832: “You know how zealously Our predecessors taught that very article of faith which these dare to deny, namely the necessity of the Catholic faith and of unity for salvation. The words of that celebrated disciple of the Apostles, martyred Saint Ignatius, in his letter to the Philadelphians are relevant to this matter: ‘Be not deceived, my brother; if anyone follows a schismatic, he will not attain the inheritance of the kingdom of God.’ Moreover, Saint Augustine and the other African bishops who met in the Council of Cirta in the year 412 explained the same thing at greater length: ‘Whoever has separated himself from the Catholic Church, no matter how laudably he lives, will not have eternal life, but has earned the anger of God because of this one crime: that he abandoned his union with Christ’ (Epsitle 141). Omitting other appropriate passages which are almost numberless in the writings of the Fathers, We shall praise Saint Gregory the Great, who expressly testifies that this is indeed the teaching of the Catholic Church. He says: ‘The holy universal Church teaches that it is not possible to worship God truly except in her and asserts that all who are outside of her will not be saved’ (Moral. in Job, 16.5). Official acts of the Church proclaim the same dogma. Thus, in the decree on faith which Innocent III published with the synod of the Lateran IV, these things are written: ‘There is one universal Church of the faithful outside of which no one at all is saved.’ Finally, the same dogma is expressly mentioned in the profession of faith proposed by the Apostolic See, not only that which all Latin churches use (Creed of the Council of Trent), but also that which the Greek Orthodox Church uses (cf. Gregory XIII, Profession ‘Sanctissimus’) and that which other Eastern Catholics use (cf. Benedict XIV, Profession ‘Nuper ad Nos’)… We are so concerned about this serious and well known dogma, which has been attacked with such remarkable audacity, that We could not restrain Our pen from reinforcing this truth with many testimonies.”*