The life of each one of us is worthless and worse than worthless, if it does not end in heaven. Although Jesus our Savior has opened the gates of heaven for us, we cannot on our own discover the way there, or less still follow it. It has to be signposted for us, and we need to be helped along it. Just as we have the help above all in the teaching and sacraments of the Church which Jesus founded, we have the signposts in the commandments: "My son, keep my commandments, and you will live" (Prov 7:1-2); "the steadfast love of the Lord is upon those who remember to do his commandments" (Ps 103:17-18); "If you would enter life, keep the commandments" (Mt 19:17).
While Our Lord conferred his own authority fully on Peter (Mt 16:16), he also gave authority to the Apostles together as a group or "College" (Mt 18:16); cf. CCC 880. In its proper ecclesial sense, collegiality is referred to the whole body of bishops, as successors of the Apostles. Each bishop has the main mission of governing his own diocese. But, also like the Apostles, each and all together must participate, under Peter, in the concerns of the universal Church (cf. LG 23).
Collegiality has its most formal exercise in an Ecumenical Council. While the Synod of Bishops is not a parallel expression of collegiality, it tends to keep the spirit and practice of collegial collaboration strong, in service of the universal Church and the particular Churches.
When we speak of some people being "very human", or others as "lacking in humanity", what we mean is that they are fulfilling - or falling away from - the models or standards befitting human nature. "Human nature" or "what it means to be human" is not something each one decides for himself or that can be changed at will. It has an objective content: one given by God when he made man "in his own image" (Gen 1:27).
Baptism is the sacrament by which one becomes a Christian - a son or daughter of God, a brother or sister to Jesus Christ, and a member of God's Church. Nothing more important can occur in a person's life than to receive Baptism. It is a "second birth", a birth to a new and higher life - the life of God himself.