If you think that the Lottery is something new, think again. Have a look, for example, at today's first reading from Acts (1.15-17, 20-26). The apostles need someone to replace Judas. They do what selection committees still do today, they draw up a list of criteria which they use to narrow down the field. And then they draw lots. (This is how we get the word lottery - from the ancient ritual of drawing lots.)
How do we know God's will? That is always a difficult question to answer. It is so easy for us to assert that this or that is what God wants us to do - or wants other people to do - when all the time we are really asserting what we want. For example, there was a time in the 1970s when Christians tried to smuggle Bibles behind what was then the Iron Curtain; I remember a Protestant minister telling me that several young adult members of his congregation felt God wanted them to smuggle Bibles, but none of them felt called to the less romantic task of visiting the sick and elderly.
So how do we know God's will? Always, with the help of prayer. Often, with the advice of people respected for their faith and wisdom. Sometimes, with struggle and uncertainty. We might also find some useful pointers in the way Matthias is chosen in the first reading today. Note the steps the apostles take.
First, they consult scripture, finding a precedent for the action they are about to undertake. Second, they share their memories of Jesus, because they want whatever they do to be in keeping with the living memory of Jesus. Who Jesus was and what he taught: these are guides to action for them now. Third, they pray, asking God to guide and direct them in the choice they have to make. Then having done all this they do not hesitate. They act, and launch forth in faith.
Finally, let us remember what it says today in 1 John 4.16: that whoever lives in love, lives in God. If we can make our motivations and our actions loving ones, then we can be surer that we are faithful to God. However, we ought to remember that our choices will sometimes set us at odds with what the world thinks. In the gospel today Jesus reminds us (John 17.14) that the world does not own us. We may need courage to follow steadfastly in the footsteps of Christ, where his values conflict with those of the world.