The teaching authority of the Church, the Magisterium, has
 clearly stated the role of baptism in the life of the Christian.
Lateran Council IV, 1215
Infallibly defined that baptism was a sacrament of the Church.
Council of Lyons II, 1274
Infallibly redefined that baptism was one of the seven
sacraments.
Council of Trent, 1545 - 1563
Again infallibly defined the seven sacraments listing baptism
as the opening gateway and foundation of the sacraments.