The Catholic Church
The Catholic Church, originally (and still sometimes) known as "The Universal Church", is the largest denomination of Christianity with over 1 billion members worldwide. The Church's venerable history dates back to the time of Jesus Christ, the only Christian church that does so, making it the oldest sect of the Christian religion. For this reason, the Catholic Church believes itself to be the one true church and that when Jesus Christ returns He will recognize the Church as His one, true church.
The Church is centered on the belief in the Holy Trinity, or the Blessed Trinity – the idea that God is in fact three people, the Father, the Son and the Holy Spirit. This is the reason as to why Catholics are baptized into the Holy Trinity. However, Catholics pray to either Mary, the mother of Jesus Christ, or to Saints who are already in Heaven. In doing so they are sure to acknowledge Jesus Christ as their one true Savior. Catholics believe the Saints and Mary will intercede on their behalf, making their prayers more likely to be heard by God.
The Catholic Church is headed by the Pope, currently Pope Francis, who is of Argentinian descent, is also the leader of Vatican City, a sovereign nation-state. Also known as the Roman Pontiff (pontiff translates to bridge builder) or the Pontificate, the Pope is in charge of the College of Bishops and serves as a messenger to all members of the Catholic Church. Official declarations made by the Pope to His worldwide congregation must be made from his seat at Saint Peter's Basilica, located in the Vatican. Though the Pope is not allowed to change doctrine, nor is he supposed to create new doctrine, he is considered the key-holder to the Kingdom of Heaven. For this reason, all Catholics are required to heed His words.
The Church also believes in Seven Sacraments which were instituted by Jesus Christ. These Seven Sacraments are the key to bringing holiness to the soul. With these words and actions combined, the divine grace imparts to the soul and imbuing the soul with divine life that is united with Jesus Christ. This grace is the gift of salvation, which the Catholic Church believes that without it man is separated from Christ. These Seven Sacraments: Baptism, Confirmation, Eucharist, Penance, Extreme Unction, Holy Orders and Matrimony, are the soul saving grace that every person should gain.
The most important belief of the Catholic Church is that Jesus Christ, the Son of God, died on the cross and absolved them of their sins. Their savior made this sacrifice on their behalf and this is the reason for their thanksgiving. Before their sins can be absolved, Catholics must make confession before a priest, who intercedes on their behalf.