Baptism is necessary for salvation. As Christ himself said, unless one is born again of water and the Holy Spirit, one cannot enter the Kingdom of God (Jn 3.5). The Council of Trent declared: “If anyone says that Baptism is optional, that is, not necessary for salvation, let him be anathema” (H. Denzinger, Enchiridion symbolorum, ed. A. Schönmetzer 1618). Baptism incorporates all men and women into the mystery of Christ and into his body the Church. Baptism also confers a sacramental character upon the soul; once it has been validly received, therefore, baptism is not repeated. Baptism also confers the grace of justification, and effects the remission of all sins and their punishment. Adults must receive Baptism freely, and infants can and should be baptized. In the case of an emergency anyone (even a non-Christian) can baptize validly by using the proper matter (pouring of, or immersion into, water) and form (the Trinitarian formula).