Here, when the Lord tells Joshua to be strong and have courage 3 different times, He is actually giving us 3 different ways that we can find strength and courage when things are hard.
Christofferson- https://abn.churchofjesuschrist.org/study/general-conference/2009/04/the-power-of-covenants?lang=eng&adobe_mc_ref=https%3A%2F%2Fwww.churchofjesuschrist.org%2Fstudy%2Fgeneral-conference%2F2009%2F04%2Fthe-power-of-covenants%3Flang%3Deng&adobe_mc_sdid=SDID%3D052667A766D93CEF-3ED94F8E80521227%7CMCORGID%3D66C5485451E56AAE0A490D45%2540AdobeOrg%7CTS%3D1653279777
Benson as quoted bu Staheli- https://abn.churchofjesuschrist.org/study/general-conference/1998/04/obedience-lifes-great-challenge?lang=eng&adobe_mc_ref=https%3A%2F%2Fwww.churchofjesuschrist.org%2Fstudy%2Fgeneral-conference%2F1998%2F04%2Fobedience-lifes-great-challenge%3Flang%3Deng&adobe_mc_sdid=SDID%3D58857BE68E9604F6-3E77E543BE6130E3%7CMCORGID%3D66C5485451E56AAE0A490D45%2540AdobeOrg%7CTS%3D1653279806