I know the Lord has called me to go, but that doesn't stop the enemy from trying to stop me from going. The morning before I was supposed to leave for Ethiopia, I woke up and both knees were unbelievably swollen. They were very stiff and I could barely walk. Thankfully, it wasn't too late for me to go to the Walk-in clinic where I work. The doc came in and ended up draining fluid off of my right knee. He then had both knees ace wrapped and perscribed some anti-inflammatories. I spent the rest of the day laying on the couch with my knees propped up and iced when I should have been packing. Now, this isn't the first time the enemy has tried to do this. In college I was going on a Summer Project with Campus Crusade for Christ and I tore my ACL three days before I was supposed to leave and in India my right knee swelled up and it was very hard to walk or function, for that matter, in the type of setting we were in with lots of walking and lifting going on. I now know my weak areas and we'll have to start praying against these attacks in the future.

Hebrews 12:11-13 (New International Version)

11No discipline seems pleasant at the time, but painful. Later on, however, it produces a harvest of righteousness and peace for those who have been trained by it.
12Therefore, strengthen your feeble arms and weak knees. 13"Make level paths for your feet," so that the lame may not be disabled, but rather healed.