Then Joshua addressed the people: "Sanctify yourselves. Tomorrow God will work miracle-wonders among you." Joshua 3:5 (TM)
The miracle at the Jordan river came after a time of anticipation and preparation. Joshua set up the anticipation by announcing that miracles would happen the next day and the people responded with faith ["the assurance of what is hoped for" Heb 11:1 – which is the necessary human ingredient for any miracle]. He also called them to prepare ("sanctify": set apart for sacred use) themselves to have God in their midst doing wonderful things.
I wonder what would happen in church on Sunday if all of us anticipated that God would show up and do amazing things among us and if we prepared our hearts for just such an occurrence. Do you think the service might look a little different?