I can't imagine how Moses must have felt knowing that he will not be able to go into the promised land. Imagine, he has been leading the Israelites for awhile now. But instead of sulking, the Lord has special instruction for him. He is to commission, encourage and strengthen Joshua.
When something in our life doesn't go the way we expected them to be, we should seek the Lord's direction and go along with His plans. Let us not allow our emotions to overcome us, instead, continue on serving the Lord and doing His will for the glory of God!