As I grow in age and grace (!) and wisdom (!), what really have I learned?
First, that there is a God, though not everything we do in the name of God is honorable. Bertrand Russell once said, "If the universe makes any sense, there is a God!" The universe does make sense, though not always on the surface of things. But deep down, things do make sense, especially morally; and we know this whenever we aren't lying to ourselves. There's a law of karma operating at every level of life, letting us know that the air we breathe out is the very same air we shall inhale later. There is an ultimate justice in everything on earth.
Second, the mysteries of God, of the universe and of human life itself are far, far larger than we have ever imagined and can ever imagine. The older we get, the more we know how little we truly understand, how far beyond us is the great Mystery of Life, and how we need (as the mystic John of the Cross says) "to begin to understand more by not understanding than by understanding."
As little children we ask our parents where the sun goes at night. The answer they commonly give is that the sun goes down behind the trees to rest awhile. Later we learn about stars and planets and the big-bang theory and we graph it all out on PowerPoint presentations. But there again comes a time beyond PowerPoint, beyond Einstein and others when perhaps the best response is once again given in the language of children: the sun goes down behind the trees to rest for awhile. This is especially so about God and the dogmas of our faith. God is ineffable. Whatever we affirm of God falls all over itself verbally. All our language about God is vastly inadequate, The great statements about God in the Nicene Creed are more statements of the heart than of intellectual understanding.
One last bit: We desperately need more to trust Love and surrender ourselves to Love.
We need to let go of our pride, our wounds, our greed, our mistakes and failings, our past and our weaknesses. We need to give ourselves over to forgiveness. At a certain age : hopefully not too much further along the journey : our lives should be reduced to living and reflecting just one word: "Thankfulness!" That is genuine wisdom!