Youcat commented through CCC – Question n. 130 - Part II.

YOUCAT Question n. 130 - Part II. Are non-Catholic Christians our sisters and brothers also?

(Youcat answer - repeated) All baptized persons belong to the Church of Jesus Christ. That is why also those Christians who find themselves separated from the full communion of the Catholic Church are rightly called Christians and are therefore our sisters and brothers.         

A deepening through CCC

(CCC 818) "However, one cannot charge with the sin of the separation those who at present are born into these communities [that resulted from such separation] and in them are brought up in the faith of Christ, and the Catholic Church accepts them with respect and affection as brothers.... All who have been justified by faith in Baptism are incorporated into Christ; they therefore have a right to be called Christians, and with good reason are accepted as brothers in the Lord by the children of the Catholic Church" (UR 3 § 1).    

Reflecting and meditating 

(Youcat comment) Instances of separation from the one Church of Christ came about through falsifications of Christ’s teaching, human failings, and a lack of willingness to be reconciled—usually on the part of representatives on both sides. Christians today are in no way guilty for the historical divisions of the Church. The Holy Spirit also works for the salvation of mankind in the churches and ecclesial communities that are separated from the Catholic Church. All of the gifts present there, for example, Sacred Scripture, sacraments, faith, hope, love, and other charisms, come originally from Christ. Where the Spirit of Christ lives, there is an inner dynamic leading toward “reunion”, because what belongs together wants to grow together.

(CCC Comment) 

(CCC 819) "Furthermore, many elements of sanctification and of truth" (LG 8 § 2) are found outside the visible confines of the Catholic Church: "the written Word of God; the life of grace; faith, hope, and charity, with the other interior gifts of the Holy Spirit, as well as visible elements" (UR 3 § 2; cf. LG 15). Christ's Spirit uses these Churches and ecclesial communities as means of salvation, whose power derives from the fullness of grace and truth that Christ has entrusted to the Catholic Church. All these blessings come from Christ and lead to him (Cf. UR 3), and are in themselves calls to "Catholic unity" (Cf. LG 8).     

(The next question is:  What must we do for the unity of Christians?)