"When you were under the fig tree, I saw you." (John 1:48)
We presume that we would be ready for battle if confronted with a great crisis, but it is not the crisis that builds us - it simply reveals what we are made of already. Do you find yourself saying, "If God calls me to battle, of course I will rise to the occasion"? Yet you won't rise to the occasion unless you have done so on God's training ground. If you are not doing the task that is closest to you now, which God has engineered into your life, when the crisis comes, instead of being fit for battle, you will be revealed as being unfit. Crises always reveal a person's true character.
A private relationship of worshiping God is the greatest essential element of spiritual fitness. The time will come, as Nathanael experienced in this passage, that a private "fig tree" life will no longer be possible. Everything will be out in the open, and you will find yourself to be of no value there if you have not been worshiping in everyday occasions in your own home. If your worship is right in your private relationship with God, then when He sets you free, you will be ready. It is in the unseen life, which only God saw, that you have become perfectly fit. And when the strain of the crisis comes, you can be relied upon by God.
God's training ground, where the Christian weapons are found, is the hidden, personal, worshiping life of the saint.