They weren't "infiltrated". Jews, Catholic, Muslims…same same. They all decend from Abraham's religion. They all worship they same god of human sacrifice.
Which current common Christian denomination didn't descend from the Catholics?
Not true. Almost all modern "christian" denominations are Protestant, which have evolved from the Catholics, which evolved from the Jews.
Catholicism
Drawing of a baptism
Historically, the classic text from John 3 was consistently interpreted by the early church fathers as a reference to baptism.[20] Modern Catholic interpreters have noted that the phrase 'born from above' or 'born again' (John 3:3) is clarified as 'being born of water and Spirit' (John 3:5).
Catholic commentator John F. McHugh notes, "Rebirth, and the commencement of this new life, are said to come about ἐξ ὕδατος καὶ πνεύματος, of water and spirit. This phrase (without the article) refers to a rebirth which the early Church regarded as taking place through baptism (1 Pet 1.3, 23; Tit 3.5)."[21]
The Catechism of the Catholic Church notes that the essential elements of Christian initiation are: "proclamation of the Word, acceptance of the Gospel entailing conversion, profession of faith, Baptism itself, and the outpouring of the Holy Spirit, and admission to Eucharistic communion" (CCC 1229). Baptism gives the person the grace of forgiveness for all prior sins; it makes the newly baptized person a new creature and an adopted son of God (2 Corinthians 5:17; 2 Peter 1:4); it incorporates them into the Body of Christ (Ephesians 4:25) and creates a sacramental bond of unity leaving an indelible mark on our souls (CCC 1262-1274). "Incorporated into Christ by Baptism, the person baptized is configured to Christ. Baptism seals the Christian with the indelible spiritual mark (character) of his belonging to Christ. No sin can erase this mark, even if sin prevents Baptism from bearing the fruits of salvation. Given once for all, Baptism cannot be repeated" (CCC 1272). The Holy Spirit is involved with each aspect of the movement of grace. "The first work of the grace of the Holy Spirit is conversion. … Moved by grace, man turns toward God and away from sin, thus accepting forgiveness and righteousness from on high" (CCC 1989).
https://en.wikipedia.org/wiki/Born_again