The first lesson I learned from studying the book of Joshua is that the people of Israel were entering a land that God had already won for them. All they needed to do was possess it.
Looking back to Numbers 13-14 we learn that Moses sent spies into the Promised Land. Ten of the spies reported that the land could not be taken. It was inhabited by hostile tribes in fortified cities. Two other spies, Joshua and Caleb, declared that, although there would be a fight, the God who had delivered them from Egypt would defeat their enemies.
The people were afraid and lacked faith and went the majority report. The result was that they wandered the desert for 40 years. That entire generation, with the exception of Joshua and Caleb, died without entering the Promised Land. They could have entered the Promised Land anytime but their fear and unfaithfulness robbed them of the victory that God had already won.
There is a lesson here for us. How often have we seen people reluctant to accept the gift of salvation that God has given to us through the sacrificial death of Jesus Christ? How many Christians struggle with sin when God has given us the victory?
The Promised Land is a picture of the Spirit-filled life. Although the Spirit-filled life is available to every Christian, it still needs to be possessed just like the Promised Land. Possession of it is the result of an obedient walk.
6“Be strong and courageous, because you will lead these people to inherit the land I swore to their forefathers to give them. 7Be strong and very courageous. Be careful to obey all the law my servant Moses gave you; do not turn from it to the right or to the left, that you may be successful wherever you go. 8Do not let this Book of the Law depart from your mouth; meditate on it day and night, so that you may be careful to do everything written in it. Then you will be prosperous and successful. 9Have I not commanded you? Be strong and courageous. Do not be terrified; do not be discouraged, for the LORD your God will be with you wherever you go.” Joshua 1:6 - 9 (NIV)