Mark 6:13
And they cast out many demons, and anointed with oil many that were sick and healed them.
The core elements of the celebration of Anointing of the Sick are that: "'priests of the Church' – in silence – lay hands on the sick; they pray over them in the faith of the Church – this is the epiclesis proper to this sacrament; they then anoint them with oil blessed, if possible, by the bishop" (CCC 1519). This is straightforward enough, but what is really remarkable is not the mechanics of the rite but the fact that it is "celebrated" at all. How can we "celebrate" anything about being sick? Yet it is a mark of Catholic hope that it frequently pairs a word fraught with birthday cakes, party hats, confetti and balloons like "celebrate" with words like "sickness", "martyrdom", and "death". But there's a reason for that. When you know the story ends in resurrection, you know there's something to celebrate, even when it doesn't look like it now. The oil reminds us of that, because the oil is the great sign of the Holy Spirit, whose power works through the sacrament and whose ultimate mission is to raise us up on the Last Day. Whether we are healed now or healed then matters little. The point is, we shall surely be healed if we remain faithful to Christ. That's worth celebrating.