CCC 1426 Conversion to Christ, the new birth of Baptism, the gift of the Holy Spirit and the Body and Blood of Christ received as food have made us “holy and without blemish,” just as the Church herself, the Bride of Christ, is “holy and without blemish.”¹ Nevertheless the new life received in Christian initiation has not abolished the frailty and weakness of human nature, nor the inclination to sin that tradition calls concupiscence, which remains in the baptized such that with the help of the grace of Christ they may prove themselves in the struggle of Christian life.² This is the struggle of conversion directed toward holiness and eternal life to which the Lord never ceases to call us.³

1 Eph 1:4; 5:27.
2 Cf. Council of Trent (1546) DS 1515.
3 Cf. Council of Trent (1547): DS 1545; LG 40.