"Why do we want to 'control' other people's spiritual experience?"
I'm not sure I know the answer to this, except that I know that I find myself saying and doing things that sound and look as if I want to control. Partly, I think, it's because I have had certain experiences and I want to share them, so there is a positive (evangelistic?) side to this. But all too easily this becomes a desire to ensure that others have these experiences in the way that I had them - and that's where the controlling comes in. It keeps me in charge of my experiences, and therefore of theirs as well.
This need to 'be in control' of my own life runs counter to Jesus' teaching that we need to give things up in order to receive them. It is a sign of my own insecurity, even in the experience of encounter with God. The only way forward I see is to continue to look for opportunities to encounter God, in the hope that this encounter will transform me and enable me to give up control and rest in the love of God.
I think that clergy are particularly prone to this temptation to control due to the nature of their calling to teach and to pastor. Evangelism always runs into the same problems, in that we can end wanting to control how the Gospel is heard and received. Church (traditional and emerging) also has this problem, and must also face the issue of maintenance (numerical and financial).
Perhaps we need first of all to recognize the reality of the death that is the loss of control. Only then will we be able to see the resurrection that God can bring out of it.
There's more to say on this (and much more wisdom in Maggi's post). But that's as far as I've got at the moment.