Saturday, August 20, 2011

Unite My Heart

Psalm 86, a prayer of King David, is a favourite of mine.  It seems to sum up much of the Christian existence.  I often make verse 11 my prayer:
"Teach me your way, O LORD, that I may walk in your truth; unite my heart to fear your name"
While some verses can seem a little presumptuous to pray, verse two for example says, "Preserve my life, for I am godly;" we should be aware that this is the direction of life of the Christian.  Everyone who is born again has been fundamentally changed into a new being - into one who can come before God to pray with the confidence of Christ who is the perfect and godly one in each of us.

Unfortunately, we do not often share this confidence with King David.  Our recent sin is fresh in our memory, and we do not feel holy.  Whether we have said words in anger, let our gaze linger upon something we shouldn't, or have harboured resentful thoughts, our own heart is betraying our new nature and our prayer lacks conviction because of our guilt.

In such moments we must take hold of forgiveness from the Father and have him unite our heart, lest we be like the kingdom divided against itself that will fall (Matthew 12:25).  Prayer is a part of this process, but the same verse 11 gives us further advice to achieve a united heart.

The first part, learning God's ways, and learning to walk in His truth, is the same thing as having a heart united and set upon Him.  The internal conviction is not separate from the external action.  1John 1:6 from the New Testament shows us that our actions, how we "walk", must match our words which claim fellowship.  If it is clear that our actions don't meet our convictions, we should be praying for something more serious than our walk with God - our souls are likely more in step with the world and our heart is united with the devil.

Before you can worry about becoming more like Jesus, you must first seek salvation from him.  Only then will your heart be freed from the devil to become new and holy, and then the battle with competing desires will begin.  You can be sure that you are saved if you long for your heart to be united, to walk in God's ways, and to live by His truth.  In a sense, the prayer for a united heart will only be truly complete when Jesus returns and our transformation is complete, but for now we can continue to strive, and pray, and enjoy each step of progress.

Pray, with David:
"Teach me your way, O LORD, that I may walk in your truth; unite my heart to fear your name"
May God grant you to desire and to achieve this prayer.


Thursday, August 11, 2011

How do we do this thing called life?

Just recently, a Christian friend posed the question above in a Facebook status update. I have no idea what led to the question being asked, but an air of frustration, or even desperation, seemed to come through. Whether I read the situation right or not, I always feel that such questions are deserving of careful consideration and genuine answers - especially coming from brothers or sisters in Christ.

Before I get to my reply, I want to dwell a moment on some of the other responses. I was struck in two ways by some of the comments. First was the manner in which the comments were made. Despite this being a serious existential question, it was treated to humourous responses, which did have an edge of seriousness but still failed to address the gravity of the question. Second was the actual advice offered which focused on material pleasure, presumably as a source of happiness, implying that we “do life” to get as much pleasure and happiness as we can.

Now, I don’t think that it is wrong to seek happiness, but the forms of pleasure that were mentioned the most (food, sex, drugs, and the like) do not bring any lasting happiness, and if taken to excess, or in the wrong way, are severely damaging. In fact, these things have a huge potential to hurt or to disappoint! I actually think that the pursuit of happiness (or joy) is part and parcel of our number one purpose. Even more, I believe that the pursuit of joy is a divine command that, if not obvious, is strongly implicit in a plain reading of God’s revelation to us in scripture (the bible).

So getting right to it, the answer that I offered my friend is below; and I would like to explain the answer in more detail, including how our happiness is fulfilled within this pursuit. Here’s my take on how we do this thing called life:

“Love God and love your neighbour. Easier said than done but the same One who commands also enables those who try in His name.”

If I was to quote the Westminster Catechism, a document based on the bible and designed to summarise and teach the Christian faith - completed in 1647; in the very first question and answer, you might see some of how I arrived at my response:

Q. 1. What is the chief end of man?
A. Man’s chief end is to glorify God, and to enjoy him forever.

In only a short (and hopefully obvious) step, we can see that to glorify God (or honour Him) is to keep his commands, and in this is the meaning of life and the way to “do” life. Jesus summed up all of God’s commands by telling us to love God and to love our neighbour (Luke 10:26-28). Basically, love everyone but love God first. It also seems obvious that if we keep the opposite of this, i.e. not loving God or others (which includes ambivalence), is a dishonouring of God and is where all that is called “sin” is rooted.

Knowing that we should love is one thing, but managing to do that successfully for the rest of your life is another. Nobody can do it perfectly. God knows this, but He has mercy on those who try and he does not count their mistakes against them. He even goes so far as to strike any past offenses (deliberate or not) from their record. Even though we cannot love perfectly, we are still expected to try, and God has said that He will help anyone who tries. Even more, he inspires us to want to love, shows us how to love, and makes it so that we can love.

The final part of my response is about trying “in His name”. This is crucial, because anyone who tries to love in their own name and power will be seeking their own glory. Unfortunately for every person on earth and who has ever lived, we cannot accomplish this. We are unable to love “in His name”. This is because everything that we do is ultimately to serve our own pleasure in life. As fallen human beings, we need fixing before we can operate outside of ourselves. God steps in and does the fixing, often when we least expect it. This fixing process has many stages, but begins with being re-created or born again, and then the ongoing work that keeps us improving in our ability to love is called sanctification.

I realise that it is a huge mouthful to swallow, the claim that everyone is self-serving until God steps in, but that is a topic for another time. Feel free to discuss it in the comments if you are moved to reply.

As a concluding comment, I want to contrast the happiness that comes from loving God alongside the happiness that comes from the material pleasures of this world. For happiness to last it must be grounded in something lasting. The main contrast here is that God is eternal and material pleasures can only last as long as we are alive to enjoy them, many of them passing in scattered moments during our lives anyway. This means, that the only happiness we can count on for ever, and in any circumstance, is grounded in God. This is the truth and the means to do this thing called life.

May God bless you with joy everlasting!


Friday, August 5, 2011

Rolling (Parkour Drop Landing)

The following post was begun on my parkour blog but left incomplete and never published.  I've copied it over and added a little bit to finish it off.  I've ended it rather more sharply than intended because I don't have in mind the original thoughts and have instead used my current thinking on rolls, combined with my physics knowledge.

The old bit:
Rolling is one of the techniques that are most commonly seen by beginners in their introduction to parkour. The skill is not particularly difficult and it is essential to learn early on for safer landings. This article will focus on the main purpose of the roll in parkour, one of the major misconceptions of how a roll decreases impact on the body, and then finish with a description of the technique for beginners to learn. More experienced practitioners may like to use this technique for developing rolls on their weak side.

What is the purpose of a roll in parkour?
While there are different uses for the roll in parkour, e.g. dive rolls, fast direction changes, etc. we are considering the roll as used during the landing of a jump. There are two main uses within this category: to help reduce horizontal momentum for a high speed landing where it is impossible to remain standing, and to reduce the forces experienced by the body when jumping/dropping from a height. Our primary consideration is the latter - reducing forces on the body when landing from a height.

One obvious misconception is that a roll will save you no matter how high you drop from. More experienced traceurs often joke about being able to jump off the tenth story of a building and rolling in the landing to save themselves. While it seems pretty obvious that there are limits to the ability of a roll to reduce impact on the body, many people don't understand exactly why this is. The answer lies in the way a roll reduces impact forces on the body and what muscles in the body are engaged (and to what extent) during a roll compared to landing without a roll.

The new bit:
The other main misconception is that rolls transfer vertical momentum into horizontal momentum, and that this protects the jumper from injury.  Now, it is true that injury can be reduced, but the reasons are not to do with a vertical to horizontal transition.  Any momentum in a vertical direction must be removed by a force applied in the opposite direction.  And any momentum gained in the horizontal direction must be added by a force applied in that direction.  The vertical and horizontal are independent of each other in such analyses.

So the body experiences reaction forces in the landing which remove the vertical momentum.  The longer the force is applied, the greater the change in momentum.  Or for the same amount of momentum, the longer the force is applied, the lower the force needs to be to remove the vertical momentum.  The main reaction force is upwards from the ground and this transfers through the body's natural suspension system of joints, ligaments, tendons, and muscles to halt the descent.  From the physics we know that the greater the instantaneous force, the higher the chance of breakage.  

Here's the final conclusion of all that science:
A parkour roll used in a vertical landing works because it reduces the maximum instantaneous force used to remove the vertical momentum from the drop.  The force experienced by the body is spread out over a greater time during the landing.  A roll landing allows the lander to take more time in the landing by crumpling, much the same way that a car bumper is designed to crumple to absorb momentum.  

Another way to look at it is with an egg falling onto a brick compared to an egg falling onto a foam mattress.  The brick tries to stop the egg instantly because it has no give.  The mattress slows the egg more gradually and lowers the maximum force on the egg.

So why bother rolling?  Why not just crouch on the landing?  Well, for at least three reasons.  One is that you can't crouch to bring your center of gravity as low as you can get with a roll, this means a roll is better at increasing the amount of time taken to land.  Two is that very often there is some horizontal momentum from the jump which means a roll is a more stable technique for landing.  Three is it is possible that more muscles can be recruited to spread the force out between while rolling because a greater body tension is required for the execution of the roll.

This information can inform our rolling technique.  Instead of just copying a video, you now know what to do to have the most effective roll.  You need to make your landing last as long (and as smooth) as possible to ensure the lowest possible force on your body.  This means resisting the landing from the highest point all the way down to the lowest crouch possible before rolling to continue the descent a fraction longer.

It is worth mentioning that the roll is also just smoother and allows you to regain your feet easily.  Paratroopers in past wars have used a crumple method of landing that didn't rely on getting to their feet again.  They would crumple into a sideways kind of heap like the video below (about 1 minute into the clip):