I don't think that Paul was talking literally about strapping on his running shoes and pounding out ten miles, or striving to take first place in the weekend 5K. Rather, he was using an analogy to help people understand what he was saying about living the faith.
Do you not know that in a race the runners all compete, but only one receives the prize? Run in such a way that you may win it. Athletes exercise self-control in all things; they do it to receive a perishable wreath, but we an imperishable one. so I do not run aimlessly, nor do I box as though beating the air, but I punish my body and enslave it, so that after proclaiming to others I myself should not be disqualified.
(1 Corinthians 9:24-27)
Our ultimate desire should be to be with God in heaven for eternity. So when we live our life, we should live with that goal in mind. We should always aim for heaven, and that means keeping our focus on Christ, who is the way the truth and the life. Too many Christians do not live for Heaven, but rather to avoid hell. The problem with aiming for Purgatory is that, if you miss, it's all over. If you aim for Heaven and miss, you still have a shot at a concession prize. Paul tells us that we should run to win, not just to finish.
A popular speaker, Matthew Kelly, has used the analogy of running a marathon. If you went out tomorrow to run a marathon, could you? What if you tried really hard? Most of us just would not be able to do it, because we haven't trained to do it. That's because trying alone isn't good enough; you've got to train. If the race is analogous to spiritual growth leading to heaven, then how do we train? We start by going to mass, but a runner who wants to be competitive isn't going to reach peak performance if he only runs once a week. We've got to do the things that are necessary to enter into a closer relationship with God: frequent the sacraments, pray daily (Paul says pray continuously), read and study the Bible. Let your growing love for Christ express itself in love for your neighbor through charity and service. Exercise self-control in avoiding sin and the things that lead you away from God.
Don't just run aimlessly, Paul tells us. Don't be a minimalist Catholic, doing only the things that the Church says you have to do, and those grudgingly.
Nobody says that training for the race is easy, but isn't that what we admire so much in our star athletes? You're not likely to see a champion runner compete in a parka and snow boots. That's because they are heavy and restrict motion. They slow the runner down. That's what our sins do. And I'm not just talking about the mortal sins -- the big ones -- even the venial sins are encumbrances that can cause us to fall just shy of our goal. We have to shed our disordered desires and detach ourselves from all the things around us. They might be good things, and we can use them and enjoy them, but we must not let them become more important to us than our ultimate goal: the beatific vision. That would be like running in a beat up pair of sneakers that we've had forever, when a new pair could give us that extra performance that makes the difference between winning and being an also-ran.
Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight and sin which clings so closely, and let us run with perseverance the race that is set before us.
We also have to remember that, while nobody else can run the race for us, we are not running alone: "we are surrounded by so great a cloud of witnesses." The saints who have already finished the race ahead of us have returned to line the final stretch, cheering us on. There are other runners also competing who are on our team. We support one another in the race. We train together for race day. Just as the amateur athlete might look to the professional to see how they train, we can look to the saints to see how they lived their life, what they did to grow close to Christ. They don't just cheer for us, they give us an example. They are our role-models.
Another way to think about laying aside every weight is to think about the importance of a good diet for the competitive athlete. Peak performance athletes don't typically live on a diet of greasy hamburgers, french fries, and soda. They eat healthy food, aware of the nutritional value of what they put into their bodies and the effect that it will have on their performance. They might carefully watch what they eat before a race to ensure the maximum amount of energy is released to their muscles when they need it. If we are to run the spiritual race to win, we must be careful about what we feed ourselves with spiritually. The formation of an individual's conscience is a very important thing, and a malformed conscience can cause us to run erratically, and could result in spiritual injury that could prevent us from even finishing.
We also have to run the race that is set before us. We don't get to choose the course, it's already laid out. Spiritually, we have to live the life we've got. We can't waste our time living someone else's life. I'm a husband and a father of six, one of whom has special needs. That's the race that I've got to run. It does me no good to try to run the race of a cloistered monk -- that's not the course that is set before me. This is where I am, and this is where I have to find God's will for me.
In a race, if you break the rules, you could be penalized or disqualified. Christ gave Peter the keys to the kingdom, along with the authority to bind and loose. The Church has defined some things as intrinsically evil. Do those things, and you'll probably find yourself disqualified. At any rate the Church lays out the rules and offers plenty of coaching advice. You break the rules at your own peril. I wouldn't recommend it.
An athlete is not crowned unless he competes according to the rules.
(2 Timothy 2:5)
It is our hope that, at the end of our life, we will cross the finish line and enter into the embrace of God almighty.
I have fought the good fight, I have finished the race. I have kept the faith. Henceforth there is laid up for me the crown of righteousness, which the Lord, the righteous judge, will award to me on the Day, and not only to me but also to all who have loved his appearing.
(2 Timothy 4:7-8)