Imagine God Himself saying this to you today. Seriously. Right now. It's okay. I'll wait. Take your time. Maybe you should re-read it. Whatever you have to do, please internalize this passage of Scripture. You might memorize it, you might type it out and put it on a mirror, but please get this in your spirit.
Joshua allowed what God said to transform his life. He used to be Moses' sidekick/Leader of the Israelite army, now he's taking Moses' place as the leader of the people called Israel. Joshua will need to be firmly rooted in Scripture and in courageous thinking and living (if he had not already); and by this statement, he might have been great at being the 'five-star general', but being 'president' is another story.
The nation of Israel had been led by "The Hornet" or "hornets" up until they crossed the Jordan River. Now, as they enter the Promised Land, there is a new person, the Angel of the Lord, just as the human representative leading the nation of Israel is changing from a miracle-working leader/prophet (Moses) to a leader/warrior/prophet (Joshua).1 Changes must come. You must be humble enough to accept them. Know they are for your good.
There is no authority without being under authority. No man is an island. No human being has ever become a self-made man. Nobody.
Joshua was one of the two young men (he and Caleb) who had a good-and-faithful-servant's report about the Promised Land. As you read in Exodus 17, the first mention of Joshua is that somehow he had already been appointed the aforementioned general over the armies of Israel. There was no fanfare or miraculous moment for Joshua to enter the story, just a benign mention of him being the leader of Israel's army and a display of overcoming faith and humility in a heart that agreed with the truth that God is more than able to do all we can ask or imagine. (Even Jesse, David's dad, would not expect much from his youngest son until Samuel came to anoint David as Saul's successor.)
The main reason we have changes at critical times in our lives is because the way we were (and/or the human being(s) leading us) will not get us to where we must go next. If you have been dealing with those awful feelings of impending doom and discouragement, know God is about to change your direction because you cannot make the next leg of your journey with your current configuration of situations and people. You need more of God. As a believer, and follower, in Jesus Christ, you are automatically called to leadership. You must know that God has your back and He will guide you into your own personal Promised Land.
Prayer
Lord God in Heaven, You are all we need. You are all I need. I ask that You would reveal my new set of circumstances and help me to recognize what You would have me do in all situations so I can start or continue in this more intimate journey with You. Embolden and encourage me today as You did with Joshua. I pray that You would bring a leader into my life who would guide me as You would guide and train me as You would have me go and become all you made me to be. I would prefer if You would be my mentor, Lord, but I will accept a human being just as humbly. Open my eyes and let me see what I need to see and open my ears so I can hear what the Spirit is saying to me and to others. In Jesus' name, amen.
Footnotes
1 This is a great thing to consider because this human exchange is a very clear foreshadowing of the Messiah/Son of Man the Jews were told to anticipate. Jesus' initial coming was reminiscent of Moses' personage/position while Jesus' second coming will be reminiscent of Joshua's personage/position.