Form and Matter: Why Taco Chips Can't Be Consecrated and Women Can't Be Priests.

For a sacrament to be valid, it must be properly celebrated — that is, certain requirements set forth in Church law must be met. For this reason, no sacramental rite may be modified or manipulated except by the supreme authority of the Church, which itself may not act arbitrarily but always “in the obedience of faith and with religious respect for the mystery” of the sacramental liturgy (see no. 1125). Thus it belongs to the Holy See alone to set forth in law what constitutes the proper and valid celebration of the sacraments. http://www.osv.com/tabid/7631/itemid/10245/Matter-and-Form.aspx

The Creator made these Sacraments as Avenues of Grace (Spiritual Power) to Strengthen us in This Life for Eternal Life.