How can we know the living God and attain to everlasting union with God? This is really the only question of life. Kreeft's dialogue with Aquinas shows us what it means--existentially, not solely academically--to learn from a saint.
"In the beginning God created the heavens and the earth." This is such a reassuring thing. The world is in God's hands; it is his world. We sinners have messed things up and the amount of human division and cruelty is so terrible, but fortunately God is God.
I think that the authority of Scripture must be accepted by Catholics and Protestants, and that if our doctrinal judgments are not measured by Scripture, then we'll be found lacking, since Scripture communicates divine revelation to us.