Joshua 1 God Commissions Joshua To Be Awesome

As the Book of Joshua opens, Moses is dead and God gets it in His mind that the Israelites need a new leader.
Enter: Joshua, son of Nun.
For clarification, when we say Nun, we mean Joshua's father, not a lady in a headpiece. Or, for that matter, without a headpiece. Capisce?
Joshua's first duty is to have the Israelites cross the River Jordan.
It is unclear if Joshua wonders why they have to do this, but God clarifies anyway by saying that "every place that the sole of your foot will tread upon I have given to you, as I promised to Moses. From the wilderness and the Lebanon as far as the great river, the river Euphrates, all the land of the Hittites, to the Great Sea in the west shall be your territory" (1:1-4). Oh, okay. Thanks, God.
Now that Joshua has his mission, he's ready to begin. Or his he? Apparently, God isn't done talking. He seems to want to be sure Joshua knows He's got his back (1:5-7). Let's just say God might be a little wordy, too. We guess when you're an omnipotent being and you control all time and space, though, there's really no reason not to take up a few extra seconds.
Now that Joshua is assured, he's ready to hit the road.
Except he doesn't.
Joshua goes through the camp commanding the people to pack up because in three days it's gonna be river crossing time.
Remember three things: (1) the number three is important in the Bible, (2) the Israelites are nomads so they have very little possessions to get ready, and (3) there is no number three. We're just emphasizing that the number three is important. See number one for clarification.
After Joshua is done telling everyone what to do, the people of Israel decide to say in perfect unison (as is the biblical way), "Just as we obeyed Moses in all things, so we will obey you. Only may The Lord your God be with you, as he was with Moses" (1:17).
That quote right there is irony, ladies and gentleman. If you remember from Exodus and Deuteronomy, the Israelites were notoriously bad at following Moses's directions. To be fair, Moses was pretty bad at following his own directions too, though.
The Israelites finish their speech to Joshua by saying "Only be strong and courageous" (1:18).
This phrase comes up a lot in the first chapter of Joshua. We think it's safe to bet that "strong and courageous" might be a central theme of this story.
Remember, the Israelites at this point in their history are a warrior nation, and warriors pride themselves on being strong and courageous.