I was speaking with someone who has lost heart because going to Mass seems to do nothing for him. There is no spiritual experience involved, so that he is just going through the motions. It increasingly feels like a waste of time, if not actual hypocrisy. The answer to this problem, I think, lies in how we participate. The Mass is the greatest-ever work of "spiritual engineering". Like a suspension bridge over some huge chasm, or a giant piece of machinery, it is intended to do something. But in order for it to do its work, you need to cooperate or participate. You do have to walk over the bridge, or turn the machine on. Most of the time we don't do that: we just watch. The only way to participate is to give ourselves spiritually - that is, in our will, or intention - to the action of the Mass. The Liturgy of the Word at the beginning of Mass, with the act of contrition and the reading of Scripture, is designed to prepare us to do that. The actual giving takes place in the Offertory, when we add our hearts to the sacrifice. The first part is like a kind of "melting" of our hard hearts, which are frozen in a particular configuration, a particular shape. We are supposed to then "pour ourselves" into the Mass, just like molten metal is poured from a crucible into a mould, where it can be set into a new shape. But this is harder than it sounds. We tend to want to hold at least part of ourselves back. We are afraid of changing, or we are attached to something we don't want to let go of, which we can't give to God. That is the struggle, and it is that which makes Mass interesting. But to the extent - even if it is a limited extent - that we manage to let go and to give something of ourselves to God, he is able to do something with it, and we will immediately start to feel something very definite, something subtle but unmistakeable, which confirms to us that the process is happening.