6 Be strong and of good courage, for to this people you shall [a]divide as an inheritance the land which I swore to their fathers to give them. 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 [b]prosper wherever you go 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. 9 Have I not commanded you? Be strong and of good courage; do not be afraid, nor be dismayed, for the Lord your God is with you wherever you go.”
In this text, God is calling Joshua as the new leader to lead the Israelite to the promised land. God is telling Joshua to be "strong and courageous". It was Joshua's purpose to lead the next generation to the land that God has promised them. The same goes for us as children of God. Whatever God is calling you to do, God will give us the courage and strength to do it. We just have to be willing and obedient. We all have a purpose on this earth to build the kingdom of God. Be strong and courageous enough to do it.