What place do ritual and ceremony have in the church today? (Liturgical POV)

I've already asked this to get a non-liturgical point of view and now I would like to see an answer from a liturgical Protestant, Catholic, or Orthodox view. Scripture, especially in the Old Testament, goes into great detail about the specific ways of doing certain worship-related things. For example, The ordination of Aaron is a highly ritualized procedure. The sacrifices are each a little different and are laid out as detailed rituals performed by priest and worshiper. Even the camp around the tabernacle was highly organized and only set out when the trumpets were blown a certain way. However, it has been argued that these external forms have passed away and that all (or nearly all) that remains is the inward truth. Given the fact that Christ has come to fulfill the law (Mt 5:17) and that He has brought an end to the sacrificial system as it was (Hbr 9:23ff arguably implying an end to all the surrounding ritual as well), what biblical basis is there for keeping ceremony and ritual? This would apply both in the worship service and outside, for things like weddings and the like.