What's knocking you off course?
"Therefore we also, since we are surrounded by so great a cloud of witnesses, let us lay aside every weight, and the sin which so easily ensnares us, and let us run with endurance the race that is set before us, looking unto Jesus, the author and finisher of our faith, who for the joy that was set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God." Hebrews 12:1-2
In this life, everyone is running a race of some sort. Maybe you have a career, a passion, or even a simple hobby. You have a goal, you're learning everything you need to know about it and taking steps to achieve it. I'm sure you're aware that if you make mistakes on your path to achieving your goal, it will cause trouble and even prevent you from finishing. You know the importance of staying on path.
Above is an illustration of the space probes Voyager 1 and 2 as they made their way out of the solar system. The paths were well-plotted before the probes even launched, otherwise the missions might have ended in disaster before completing any of the objectives. The mission planners had to make sure they didn't crash into any of the planets they intended, nor did they want to crash into any of the surrounding moons or asteroids that might end up in the way. Everything in space is moving and it's all moving extremely fast, like tens of thousands of miles per hour. Fortunately, everything is on an orbital path thanks to gravity. Nevertheless, it's a nail-biting situation to be in looking at all the possible things these probes could crash into.
Not only do the mission planners have to plot a careful path, but the engineers have to make sure the navigation equipment is able to stay on the carefully plotted course. If they were to deviate ever so slightly, it would amount to a massive difference in the long run. For instance, if it were to only deviate 1 inch for every mile it traveled, the Voyagers by this point would be over 2 million miles off course!
Looking back to my previous post What-can-we-learn-from-Apollo-13 there's a lot to learn from the Apollo 13 mission. One of the many issues they faced was a shallowing trajectory on the way back home from the moon. As the spacecraft heads back home, it had to enter the atmosphere at just the right angle or it would end in disaster. If the angle were too deep, the crew would be crushed by the G-force of reentry and the craft would burn up. If it were too shallow, the craft would bounce off the atmosphere and launch the crew back into space. Keep in mind they were travelling at 25,000 mph by that point, which is fast enough to escape Earth's gravity. Therefore, if they missed reentry, they would be shot back into space to orbit the Sun forever. There was no chance to go up and rescue them, at least not before their limited oxygen supply ran out and they died.
At the time, neither the crew nor mission control could figure out why the spacecraft was continuing to go off course. However, upon further tests after the crew returned safely, they discovered a small puff of steam coming from the lunar module was causing the craft to go off course. They knew the lunar module gave off steam, but in the original mission it wouldn't have had enough time to cause trouble as it would only be operational for a few hours. In this case, however, it was making a straight line back to Earth on a 250,000 mile trip moving at an average speed of 3,500 mph. Therefore, a minor detail quickly became a potential for disaster.
Is there something knocking you off course?
Do you have any secret sin that you deal with? That, my friends, is the small puff of steam that will cause you to miss your mark at the end of your life! You are taking a journey through life moving at high speed, too fast to take back anything you do. Oh sure, a little "white lie" here and there, go ahead and download that music without paying for it, use God's name instead of a curse word, look at that beautiful woman with lust in your eyes as long as you don't actually do anything. Do you see how all of that can cause a problem?