Titian's Abraham and Isaac (1542-1544)
The struggle of spiritual faith and logical reasoning.
 And Abraham stretched forth his hand, and took the knife to slay his son.
 And the angel of the LORD called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I. And he said, Lay not thine hand upon the lad, neither do thou any thing unto him: for now I know that thou fearest God, seeing thou hast not withheld thy son, thine only son from me.
Even if you haven't read the Bible or heard the verses of Genesis recited, you're probably at least vaguely familiar with this harrowing, grotesque story. Abraham was called to be the father of a nation, the father of the tribes of Israel, and as such he needed to be tested by God. Thus Abraham was instructed to kill his son Isaac for the Lord. As depicted in Titian's highly dramatic rendering, an angel of the Lord stopped Abraham's knife just before striking his son. At that moment God knew that he had the right guy for the job, since he, Abraham, was willing to sacrifice his son due to his fear of the Lord.
The struggle here is obvious, and it divides many people when it comes to the God-based religions. The question inevitably arises, "What kind of God asks his people to kill their own children just to prove their loyalty?" Such is the struggle to reconcile spiritual faith with human logical reasoning.
The struggle of loneliness and late-life achievement.
The first of the four movements.
It seems that all too often geniuses are plagued with mental insanity, or at least attributes of psychological breakdown. Think about Schumann, Schubert, Poe, Rimbaud, Kerouac, and a host of others who've struggled with mental balance and meaning and loneliness in the midst of possessing the greatness of creativity. It seems almost as if the human mind does not have the capacity to handle (what we think of as) normalcy and genius--the two are, in a way, mutually exclusive.
In the case of Finnish composer Jean Sibelius (whose work, Finlandia, I highly recommend), the struggle of loneliness and late-life achievement (the search to produce more of his art) culminated in a dependency on alcohol. He even wrote that he had no friends left to turn to--they were all dead--and alcohol was the only substance sustaining his life. He desperately sought to continue creating his art in the face of isolation and hopelessness.
Yet in the face of this despair, Sibelius produced these beautiful, if ghostly, late works, including the sixth.
Armstrong's A History of God: The 4,000-Year Quest of Judaism, Christianity, and Islam (2004)
The struggle of religious reconciliation among many diverse peoples.
I've only read 100 pages (~1/4) of this book, but already I feel as though I've amassed a whole college semester's worth of theology, cosmology, history, and religious thought-provocation. Karen Armstrong is a fantastic writer. She is able to take a lode of information on complex topics and forge them into a clear, lucid text for the lay reader. In A History of God, her purpose is to tell the story of the way in which people have conceived God throughout history. Most striking is the more objective perspective Armstrong brings to the history, a tough thing to find in the branch of religious literature. By that I mean that she sticks to the form of a historical survey rather than a religious tract or one-sided iconoclastic antagonism.
At the same time, Armstrong keeps the current skepticism and atheistic perspectives in mind, and she even views them as new ways in which to conceive God. Indeed, the ways in which humans has understood God have changed throughout history; and ipso facto, the ways in which people have denied the existence of God have changed too. Note, for example, this excerpt from her introduction:
Like any other human activity, religion can be abused, but it seems to have been something that we have always done. It was not tacked on to a primordially secular nature by manipulative kings and priests but was natural to humanity. Indeed, or current secularism is an entirely new experiment, unprecedented in human history. We have yet to see how it will work. It is also true to say that our Western liberal humanism is not something that comes naturally to us; like an appreciation of art or poetry, it has to be cultivated.
Armstrong's purpose is not to deliver more theology, but to narrate the ways in which humans have understood God. Not Jesus; not Christianity; but God, El, Yahweh. And already in the first 100 pages it is remarkable to gain a perspective of the Hebrew people in their historical context. For example, the Hebrew people at the time described in the Old Testament did not have the concept of philosophy or scientific reasoning (though, of course they would be surrounded by this in the Hellenized world). Instead they were very pragmatic, and this pragmatism played into religion. They accepted God because God worked for them. He solved their problems, so no matter whether he fir a philosophical proposition or a mathematical proof.