Initially, Christian worship consisted of group prayer and commentaries on sacred texts and was conducted in private homes. The growth of Christian communities, changes in the act of worship and the establishment of a Church hierarchy led to the need for more suitable places for gathering. Christian places of worship took their inspiration from the basilica, a large space used for legal, commercial and administrative purposes. Baptism, the sacrament of admission, resulted in a new construction, the baptistery, being added to the basilica.