As someone who suffers from chronic fatigue, I am very familiar with the trials of weak flesh. Both the negative judgments that follow it, and the temptations that accompany it. Out of step with today's verse, I want to use Jesus' own words to show that having weak flesh is not just a lame excuse. Even a truly healthy person struggles sometimes, and different people do have different strengths and weaknesses. My own illness is particularly capricious. Sometimes I can be extremely spritely and capable of walking a 4 mile round trip. Other times (and this is far more common), I am unable to move more than a few feet without pain. And so I do wish to exhort the Church to show compassion to everyone in their weakness.
But back into step with this verse, Jesus has a warning: Watch and pray, lest you enter into temptation. It can be very tempting to use our weaknesses as a lame excuse. "I'm only human!" we cry. Ok. That doesn't really give us license. A failure is a failure, and even in compassion, failures do lead to natural consequences that must be dealt with.
Avoiding temptation is a joint effort between you and God. You have to know your limits. You have to know where you are weak and where you are strong. If you are weak, there are measures you can take. Jesus said (metaphorically, of course) that if your eye causes you to sin, pluck it out. So, whatever there is in your life that tempts you, you have to avoid it at all costs.
But if you think you're enough on your own, you're sorely mistaken. I remember a while back, there was a gala in my local area, and I went around all the stalls asking for information about the charity they represented. One of them was an addiction charity, run by Christians. They boasted a more than 80% success rate: Their clients broke their addictions permanently. But he also told me that similar programs run by the government had a significantly lower success rate. Their solution? Jesus. While the government wanted the charity to remove Jesus, even refusing funding to the charity, the charity themselves responded "if we get rid of Jesus, we'll fail just as often as you do." And so Jesus gives us another element to overcoming weak flesh: Watch and pray.
So you see, there are two elements to defeating the weakness of our flesh, not just one. For too many people, the solution is to pray, but not watch. They rely too heavily on God, and worse, when this inevitably leads to failure, they have the cheek to blame God. On the other hand, there are those who think "I don't need God, I can do this on my own!" The result: They feel wretched when they fail. Now, that's not to say they aren't wretched. We all are. That's kind of why the crucifixion had to happen. But this is really just the flip side of pride.
Only when we work together with God can we be conformed to the image of God. If we get too lazy, too much of our own image creeps in, and if we don't rely enough on God, the image of God doesn't go where it needs to be. You can't take out what you don't put in. Thus, Godliness is a healthy combination of prayer and action. Faith without works is dead, works without faith are dead. Live! Do your good works in good faith, and do good works to show your faith.