1. TO SERVE GOD FAITHFULLY, ONE MUST BE STRONG & VERY COURAGEOUS.
Joshua 1:7 - "Only be strong and very courageous, that you may observe to do according to all the law which Moses My servant commanded you; do not turn from it to the right hand or to the left, that you may prosper wherever you go."
To serve God faithfully, one must first learn what God requires. Then, one must possess the strength and courage to implement His will. Getting distracted or sidetracked to either the right or the left will not do. One must stay right down the middle with the Lord. Such a one will be greatly blessed.
2. MEDITATING ON THE WORD OF GOD IS IMPORTANT FOR ANYONE WHO WANTS TO LIVE OBEDIENTLY & BE BLESSED BY GOD.
Joshua 1:8 - "This Book of the Law shall not depart from your mouth, but you shall meditate in it day and night, that you may observe to do according to all that is written in it. For then you will make your way prosperous, and then you will have good success."
There is a difference between being familiar with something and really knowing it thoroughly. God's people must know His Book thoroughly, which requires intellectual effort (meditation; cf. Phil. 4:8) and time. Knowing the Book makes it possible for one to then comply with its teachings and reap great blessings. It is impossible to obey what one does not know (cf. Hosea 4:6).
3. MEMORIALS CAN BE EXCELLENT TEACHING TOOLS.
"Then he spoke to the children of Israel, saying: 'When your children ask their fathers in time to come, saying, "What are these stones?" then you shall let your children know, saying, "Israel crossed over this Jordan on dry land"; for the LORD your God dried up the waters of the Jordan before you until you had crossed over, as the LORD your God did to the Red Sea, which He dried up before us until we had crossed over, that all the peoples of the earth may know the hand of the LORD, that it is mighty, that you may fear the LORD your God forever.'"Memorials are great object lessons waiting to be expounded upon. They cause the next generation to ask questions and thus provide a perfect opportunity to explain the past and instruct for the present. Those who hadn't witnessed the miracles could be told about them, so they might believe and serve the most High God (cf. John 20:30,31).
4. WHERE A PROBLEM CAN BE SOLVED BY NATURAL MEANS, THERE IS NO NEED FOR A MIRACLE.
Joshua 5:12 - "Then the manna ceased on the day after they had eaten the produce of the land; and the children of Israel no longer had manna, but they ate the food of the land of Canaan that year."
The children of Israel had eaten manna for approximately forty years. They had become accustomed to it, for sure. Why had God sent it that long? Because it was needed. The people would not have survived without it. However, once the food of Canaan was available to them, they no longer needed the miraculous bread from heaven. Today, God has given us everything we need to know in His Scriptures; all matters of doctrine can be settled via the inspired word of God (cf. II Tim. 3:16,17; II Pet. 1:3; Jude 3). Thus, no longer are miracles needed to reveal or confirm a message from deity. Although it would be nice to still have them in some regards, God knows we no longer need them and thus He removed them (cf. I Cor. 13:8ff) as He did the manna after it became superfluous.