1 Kings 18:37 Give me an answer, O Lord, give me an answer, so that this people may see that you are God, and that you have made their hearts come back again.
Turning the Hearts Back to God Again.
Revival could be described as the invasion of a place by the Spirit of God, which causes the hearts of people to come back again to the Lord.
Of course this is also a definition of repentance, the turning away from sin and turning to the Lord. I submit there is a definite connection between repentance and revival.
This phrase also defines salvation and restoration which revival also includes.
Additionally I am struck with the thought this phrase could describe intimacy. It describes those whose hearts were not close after God but now have become so.