Those who come together for liturgy do not have the luxury of acting as passive "pew potatoes," waiting for all to be done for them. The liturgy is not only their right, it is their duty, their responsibility, and that responsibility includes full engagement throughout the liturgical celebration.
The baptized faithful who form the congregation are called to join in praise and thanksgiving in song and spoken word; to listen attentively to God"s Word, to exercise their baptismal priesthood in prayer for the Church, the world and all in need during the General Intercessions.
In the Liturgy of the Eucharist they join their prayer to that of the priest celebrant, offering Christ the Victim, not only through the hands of the priest, but also together with him and offer themselves as well (General Instruction of the Roman Missal, no. 95) and their participation culminates in the reception of the Body and Blood of the Lord, the sacrament which unites them more fully with Christ their Head and with one another.
(U.S. Conference of Catholic Bishops on "Ministries and Roles within the Liturgical Assembly at Mass")