I don't believe Catholicism is Christianity. Not to say God's elect people can't be Catholic, just that the church itself is an apostate, Antichrist institution.
From the original Westminster Confes...
The Catholic Church is the true Church of Jesus Christ, founded by Him upon Peter and the apostles (Mt 16:18), as one, visible, and united. In it fully subsists the Church of Christ, with all the means of salvation, marked by unity, holiness, catholicity, and apostolicity. Governed by the Pope and bishops in communion, it is the Mystical Body of Christ, inseparable from its Head. Elements of truth exist outside, but the fullness is uniquely in the Catholic [Church], according to Vatican II. Scripture condemns divisions (1 Cor 1:10). Thus, only it is the Church founded by Christ.