The irony of grace and wrath
Edwards' Sermons are difficult to parse because they attempt to explore the paradoxical relationship between two very confounding concepts. On the one hand, there is the threat of judgment that the Bible portrays in stunning detail, but on the other hand there is the promise of everlasting kindness and love that God maintains throughout judgment. One might be shocked to discover Edwards' opinion that mankind is secretly positioned on a judgment seat, as discussed in Sinners in the Hands of an Angry God which is quite horrifying.
Life and irony
Edwards' opinion is that life is deeply ironic, because the sensory experience of the human life seems to explain itself. It seems obvious that we should exist, because after all—we do. But logically speaking, there is simply nothing to "prove" with scientific certainty that this reality is not as Edwards suggests, an artifice of some divine conspiracy to judge humans for their behavior and beliefs. Edwards is suggesting that the daily life we lead is only a game through which we illustrate our virtues and vices to a heavenly judge.
Superiority and inferiority
The truth about human life is ironically superior and inferior. The irony of human superiority can be simply explained this way: Among animals, humans are like gods, because we can cooperate and build on each other's accomplishments through language and technology. Typically that leads to a superior opinion of our individual selves that can often cause competition, but Edwards maintains that this is just a divine joke at our expense. In the end, he suspects we will all discover that we are infinitely inferior to the ultimate being of God.
Suffering and irony
To properly diagnose the irony of suffering would take an entire book of theology, but it is important to mention it because Edwards (famously and infamously) considers this issue to be at the very center of human relationship to God. Although suffering seems to demand an explanation, and although much of human suffering seems rooted in tragedy, mishap, or coincidence, Edwards feels all human suffering is a punishment designed to discipline the human soul out of its evil state. Needless to say, this is among his more controversial statements.
Dependence
The irony of dependence is much like the irony of superiority. Although the general plot of a human life is to move from dependence toward independence, as a child becomes an adult, the plot of the divine story is that slowly, a faithful servant of God will become more and more aware of their unimaginable dependency on God for everything. This includes provision, but also other aspects of life. God's design of a human's life is their only hope for happiness, says Edwards, despite human agency and free will.
