The gods of Egypt were not simply trinkets that were picked off the shelf at Wal-Mart because they fit the decor. They represented the core of Egyptian society: what made them great: and thus what needed to be taken down in order to truly liberate the people of Israel.
If this is the case, there is much more to understanding God's assault against Egypt than just freeing the Covenant People.
One theory is that each plague is represents a condition of our own heart that needs to be conquered before we can be liberated from sin.
The first, plague (river turned to blood), was graphically impressive; but no more than an inconvenience. The Egyptians couldn't just go to the water's edge to draw. They had to dig wells in the sand along the river's bank. But, the Nile represented the strength and greatness of Egypt. It was their source of confidence. The first thing that God demonstrated was that that our confidence is often misplaced. Sure, the Egyptian magicians could mimic this plague: we can continue to hold up a false-confidence, regardless of the facts, but the inconvenience of truth can't totally be ignored.
The second plague (frogs) may be understood as coldness in our relationships: we go through the motions of what we know or suppose to be right; but there is no personal warmth or feeling attached to it. In Hebrew the plague of frogs in unique in that the word for frogs is always singular. It is the plague of frog. Even when they piled up heaps of them in their houses, it is described as heaps of frog. Since, as a society, we draw warmth from each other, the second plague can be understood as an emotional disconnection: a coldness toward those around us.
The third plague (lice or gnats) have been said to demonstrate an unhealthy sense of submission. One gnat or one nit is of little significance, easy to ignore; but the power of numbers can be overwhelming. We use this same reasoning in the way we set our moral compass: if so many others are doing it, it must be okay. This only works if we manage to create our own micro-majority. Islam is the fastest growing religion in the world. Does that make it right? Trusting in the power of numbers is a plague that is destroying us from within.
The fourth plague (flies) has been described as unharnessed ambition: the wild desire to achieve one's own goals, only to leave what remains covered in filth and useless.
Fifth came the inexplicable death of cattle. The Zohar (a Jewish commentator in the 2nd Century AD) explained that the Hebrew words chosen to describe this plague represents a false sense of compassion: we love our livestock, we care for them, only so that we may eat them. When we only demonstrate a sense of compassion for something (or someone) only so that we may use them, we are living this plague in our lives, often never realizing why our relationships wind up so destructive.
In the sixth plague, burning embers are taken from a furnace and hurled in the direction of the people. This may describe the way we can be so brutal in the manner we reject other people.
Storms of hail mixed with fire can demonstrate the destructive paradox we find in arrogance. We shoot people down, just to demonstrate how we are exalted.
The last three plagues are grouped separately from the others. Some have suggested that, while the other plagues represent a trite and selfish mind, the last three plagues run deeper.
The plague of locusts may represent our intellectual ability to devour: to pick things apart until there is nothing less of value.
The ninth plague (darkness) suggests a locked mind: that there is no room for further understanding, and thus greater hope, we are incapacitated by our own feeling of complete understanding.
Finally, the death of the firstborn has been described as the loss of our own personal identity. The culmination of all the plagues, each one representing a potential turning point toward healing, defines the manner in which we die inside when we harbor our own plagues of self-will.
Solomon said, so wisely, there is a way that seems right to a man but the ends thereof are the ways of death. How unfortunate that we are so inclined to see the plagues in our lives as things that will pass: that we harden our hearts against change and reconciliation only to find ourselves drawn deeper and deeper into our own destruction.