Paul's comment of II Cor. 4:18 is a live wire to me; especially in its context of suffering is a productive force among believers. Daily renewal is present because God is present. We get to be newer today than we were yesterday. We live a perpetual rebirth.
How this happens is God's secret and mystery. I surely enjoy it. It is fun being 63 and feeling the aliveness of 3. Not all childlikeness is negative; just the childish part. But being like a child in our eagerness and gladness and energy is so the life of God.
What is there about a believing heart that feeds its renewal? First, it is totally God; His style, will, and formation. Second, a tool He seems to use to keep us there is directly connected to our interaction with the poor plus the realization of our own spiritual poverty. Blessed are poor ropes us in.
The more we fear being with the poor and the more we avoid the poor a direct correlation will be of weakening hearts for the drive of God. As one is moved to give to the underdog, the heart opens. And then when one interacts with the same, a heart of compassionate understanding and sympathy turns the heart valve to wide open.
The best thing for our kids, adults, and all skeptics is to put them in the line of where Jesus stood...with the poor. Resistance might be experienced by a few but the more we hang out with these special people the more we come into direct contact with the will of God.
What keeps the heart new? People. Helping, touching, and encouraging people puts us advantaged! Why? This is the very thing for which we were designed....people blessing people. Earth is not about Bible-Bowl moments of scripture recitation and participation. These elements groom us to be equipped to apply God's principles to....people.
If we have a knowledge of the Bible that does not put us in the center of people, we have misread the Word. As a result our hearts will not be strong enough to effectively reach the one or the many. Renewed hearts seem to continue because we make efforts to apply our faith toward helping the many in great need.