The main thing from wanting to join the Church looks – conscious and firm confession of the gospel of Jesus Christ and willingness to be under the guidance of the divine teacher all the vicissitudes not only of earthly, but of heavenly existence. On joining the Catholic Church without this key moment of faith in Christ and devotion to Him, can only speak in a certain perspective.
The second important condition is the confession, i.e. the acceptance for the non-negotiable and final truth, the entire contents of the Nicene creed, recorded by the Catholic Church as the head of the standard of faith in the fourth century of our era.
This creed encloses all of the most important Catholic tenets, by repulsion from which we come to the recognition of the authority of the Church of Christ, the Holy, the one, universal (Catholic in the original) and Apostolic. It is the Church that the Apostle called "the pillar and ground of the truth", so faith in Jesus the Church is as important as faith in Jesus Christ. It is a symbol of faith and proclaims.
Accordingly, we accept the leadership of the Church of Christ, believing in Him and trusting Him, we follow her guidance in all that relates to morality and faith. This is reflected in practice in obedience to the Church mind that teaches through the local and Ecumenical councils, and in obedience to pastors and competent teachers.
A few words about the transition from Orthodoxy
Baptism, wedding and all other Orthodox sacraments recognized by the Catholic Church, therefore, the transition to Catholic faith, the Orthodox don't need to pass. To become Catholic, it is only necessary to go to the nearest Catholic priest with a request to make you a member of the Universal Church. In some cases, after a personal interview with a priest, he may refer you to the catechism – a study of Tradition and Scripture. Although most often (in the case of satisfactory result of the interview) the priest asks who wants to become a Catholic to read the Nicene creed. Reading the symbol of faith, a person becomes a full member of the Catholic community.