The most important part of today for me, aside from remembering and honoring the innocent victims and brave emergency responders and passengers of Flight 93, is to not forget why it happened and who is to blame.
9-11 happened because radical Islamists hate the United States--it's culture, it's wealth, it's defense of Israel/Jews. Islamists hate the freedom that is at the foundation of America because it allows for liberty, and for people to make decisions that might conflict with the Islamists' view of a perfect sharia caliphate. To them, any act no matter how barbaric is permissible if done for the greater glory of Allah or to cause harm to the infidels. Alas, my understanding of history is that when religion and politics are in bed together, the usual product of that union is bloodshed.
Benghazi happened--well, we still don't have an openly acknowledged reason why Benghazi happened. It certainly was not about a YouTube video. My best understanding (cribbed from various sources) is that the Libyan mission included CIA running arms to Syrian rebels fighting against Assad (where the fighting is primarily two strains of Islamists pitted against each other, though there are some less extremist elements in the Syrian rebel forces), and another group of extremists (the Al Qaeda affiliate in Mali) decided to make a little statement and perhaps score some surface-to-air missiles in the bargain.
My point is, radical Islam is a mortal foe of the United States. Radical Islam will accept nothing but complete obedience and adherence to its vision of the world. Radical Islam must be marginalized and, when an imminent threat, crushed ruthlessly. Those who renounce extremism and allow for the peaceful coexistence of others are not my enemies, or enemies of the United States. But those who would kill another because they pray to a different god, or do not follow their particular strict moral code, those have no place in the world and are the enemy of all. Those who would give no quarter to the infidel deserve no mercy, and the sad reality is that millions who believe "death to the infidel" is a central part of good religious practice would rather die than tolerate a Christian or a Jew living peacefully nearby. Those who can change and tolerate others, all well and good, but those who do not must be dealt with, by force if necessary to prevent their ability to harm others.
The Founding Fathers understood the dangers of mixing religion and government. This is why the First Amendment of the Constitution explicitly addresses it. However, the Founding Fathers also understood the value religion has in society for contributing to moral well-being and order, at least in the Christian faith. Although often now misunderstood, particularly by atheists with an agenda, the First Amendment does not call for the banishment of religion from the public sphere or anywhere there is government involvement. Instead, it prohibits government from establishing a state religion or church, and also prohibits the government from abridging religion. I could rant for pages about how this element of the First Amendment is often ignored, but that is for another time.