I think here of Annie Dillard’s famous dissuasive to supposing God is tame, in Teaching a Stone to Talk:
On the whole, I do not find Christians, outside of the catacombs, sufficiently sensible of conditions. Does anyone have the foggiest idea what sort of power we so blithely invoke? Or, as I suspect, does no one believe a word of it? The churches are children playing on the floor with their chemistry sets, mixing up a batch of TNT to kill a Sun- day morning. It is madness to wear ladies’ straw hats and velvet hats to church; we should all be wearing crash helmets. Ushers should issue life preservers and signal flares; they should lash us to our pews. For the sleeping God may wake some- day and take offense, or the waking God may draw us out to where we can never return.
If, as we often claim, we “believe what we pray” (lex orandi, lex credendi: the rule of prayer is the rule of belief), we would do well to attend to the logic of the liturgy which suggests a certain caution in coming into God's presence, particularly to receive the Body and Blood of our Lord. As Moses drew near to the strange sight of the burning bush, he was commanded to remove his sandals for he was on holy ground. Just so, symbolically, as we move through the eucharistic liturgy, we stop periodically to remind ourselves that we are approaching holy ground and that doing so is an awesome thing. The one into whose presence we are coming is awe-inspiring and, while not wholly unknown, remains a mystery beyond our comprehension. We are aware of our failure to live lives of love and truth and trust, and thus of the distance between us and God.
Though it is not often read these days, an exhortation before the rites of Holy Eucharist in the Book of Common Prayer reads, in part:
if we are to share rightly in the celebration of those holy Mysteries, and be nourished by that spiritual Food, we must remember the dignity of that holy Sacrament. I therefore call upon you to consider how Saint Paul exhorts all persons to prepare themselves care- fully before eating of that Bread and drinking of that Cup.
For, as the benefit is great, if with penitent hearts and living faith we receive the holy Sacrament, so is the danger great, if we receive it improperly, not recognizing the Lord’s Body. Judge yourselves, therefore, lest you be judged by the Lord. (BCP, p. 316)
The liturgy is like an elaborate spiral dance in which we symbolically circle around and around the altar, drawing closer to the eucharistic mystery. At intervals in the dance, we stop to acknowledge our ignorance and sinfulness, and ask for God’s mercy as we proceed deeper into the holy mystery. In the Collect for Purity, we ask God to cleanse the thoughts of our hearts that we may perfectly love him and worthily magnify his holy Name … and we dance a little closer. We sing the Gloria, the Kyrie, or the Trisagion, each of which asks again for mercy – closer still. Then, after hearing God’s word read and proclaimed, we confess our sins against God and our neighbor, receive the promise of forgiveness, and exchange the peace, before dancing yet closer to the altar of the Prince of Peace. And on it goes—acknowledging God’s presence as holy (the Sanctus) and asking for forgiveness (the Lord’s Prayer). In every case, we acknowledge that we do not really know what we are up to, that the One with whom we are dealing is holy, and that we are ignorant, sinful and broken people in need of forgiveness and healing. And yet, by God’s amazing grace, we are invited and encouraged to draw near with confidence “to the throne of grace, that we may receive mercy and find grace to help in time of need” (Heb. 4:16)—a confidence that avoids presumption because it is born in baptism and trusts that the one who demands our transformation, loves us beyond our imagining.
More here: Baptized Into Eucharist