Start the Ignition!
The next time you feel weak in the knees, try using them to pray.Prayer is a powerful tool because it activates the power of God in your life. God is always with us through the presence of the Holy Spirit, but He won't unleash His power unless we ask Him to, and the way we ask is through prayer (John 16:24). Think if our life as a car (We choose what kind of car we want to be). God is the engine that powers us, and the Holy Spirit is the fuel. But unless we turn on the ignition by praying, we are going to sit there, nice to look at, but going nowhere. Prayer is like the spark that ignites the Holy Spirit to drive God's power.
Oh, and there's one more aspect to our illustration. We'll need a road map to tell us where we need to go. That would be the Bible - God's personal atlas for our life. Don't leave home without it.