It requires a lot of faith for runners to line up at the start of a marathon. We have to have faith in ourselves - that we have put in enough training so our bodies will hold up over the course of 26.2 miles. We also have to have faith in humanity - that strangers will be there to help us make it to the finish line.

When we move into the starting chute, we also trust that the competitors next to us will help if something happens to a fellow runner. We are there to support each other, not to dominate the competition, at least that is the feeling among the vast majority of runners. Although we are lining up with strangers in most cases, we welcome all and it doesn't matter what is a person's speed, origins, religion, race or philosophy - just that he or she stepped to the line that day to join us on a run.

We all choose to be vulnerable. We line up completely on our own with no teammates or ongoing support staff to cling to. We are essentially defenseless, as we have no tools to aid us or specialized gear to protect us, except for cushioned shoes that soften the 40,000+ blows to our feet. In most cases, we arrive at the starting line alone, nearly naked, with only shorts and a singlet, or thin t-shirt, on our bodies to keep us light on our feet.

Our events don't take place in the controlled environment of a stadium or court. Instead, we run public streets through various neighborhoods, close enough to the crowd to give high-fives on our journey through an ever-changing city, which may have surprises just around the corner.

In no other sport do you see the masses turn out to cheer on and support merely average citizens. Sure, elite athletes get the most attention, but marathons are open to all, even those that aren't yet halfway through the marathon when the elite runners are finishing. And, the crowd stays to support those middle-of-the-pack and slower runners.

In no other sport do the competitors rely on the courtesy of fellow amateurs. Volunteers never meet the majority of runners beforehand and spend hours keeping up with the seemingly endless flow of humanity on a day off from work. Yet, they treat every single runner that comes through their station as family, helping these strangers perform their best by providing hydration and other support at stations set up every few miles along the course for hours until the last of the thousands of runners come through.

Professionals, also strangers that could be spending time relaxing at home, put in extra hours to take care of medical emergencies, traffic control and other situations that may crop up.

All these components make marathons more like celebrations than athletic contests. Runners parade through the streets, feeding off the support of enthusiastic spectators that turn out for the show while dedicated volunteers keep the flow going. The celebration is not only of the human will to endure a grueling athletic contest, but also of the human spirit in which strangers come together to support each other.

While the marathon is unlike any other athletic contest, the Boston Marathon is unlike any other marathon. Not only is it the oldest continuous marathon, competitors, unless they are running for charity, have to meet a qualifying time standard to even sign up for this storied event.

For a runner such as myself, that is not a gifted athlete, making the qualifying standard is the prize. After several years, including my first several years of long-distance running in which I never dreamed I had a chance, I reached the elusive Boston standard in the Detroit Marathon. My friends joked before I left, that Detroit would make me run faster because I would need to keep ahead of all the dangerous elements the city has a reputation for harboring. Fear never entered my mind as I toed the starting line and the support from volunteers, fellow runners and officials was as caring as in any of the other 27 marathons I have run.

For average runners such as myself, who qualify by hard work, tenacity and, perhaps, some luck with perfect conditions, taking part in the Boston Marathon is a celebration of earning the privilege to be able to run this historic, prestigious marathon. I ran it in 2010 in around 4:07, which is when the peak number of runners are finishing and just before the time on the race clock when the 2013 Boston Marathon ended abruptly.

When the explosions went off, a few runners were blown down, but they got up and willed themselves over the finish line. Others, including volunteers and spectators simply enjoying the moment, didn't run away. Instead they ran right into the devastation to care for those in need without giving it a second thought that they may be putting themselves in danger.

That unplanned interruption in the Boston Marathon had the potential to shake the faith of runners, not only those competing, but others across the country. However, that questioning of faith was only for a tiny instant, if at all. Our reaction was like those strangers that rushed in, placing themselves in danger.

I still have faith in humanity and plan to continue to put my trust in the hands of strangers as I make my way on my life journey, including those 26.2-mile efforts that are symbols of the enduring human spirit.