There are several instances in the Bible where names are changed. Sometimes God changes names. For instance, Abram is changed to Abraham and Jacob is changed to Israel. Sometimes fathers change names. For example, Jacob changes the name of his youngest son from Ben Oni to Benjamin (Genesis 35:18) and King David changes the name of his son Solomon to Yedidiah (II Samuel 12:25). Given these examples it is not unusual to learn that Moses changes the name of Hoshea bin Nun to Joshua (Numbers 13:16). But the implication of this last change of name bears attention.
From the perspective of Biblical critics, the issue is the timing of a switch to a name with a theophoric element. That is to say, according to the priestly tradition a name with yeho in it (standing for the four-letter name for God) was unknown before the Exodus (cf. Exodus 6:2). Joshua was born in Egypt so his name would have been Hoshea. Only after the Exodus could his name be changed. So he was called at the battle with the Amalekites (Exodus 17:9f). Thus, the change in name reflects the new, post-Exodus practice of including the name of God in Hebrew names.
However, there is a grammatical point not to be overlooked. The name Hoshea refers to the past: “He has helped.” However, the positioning of the Hebrew letter “yod” as a prefix changes the tense to the future: “He (God) will help.” Thus the name change is less an indication of the introduction of the theophoric element in Israelite names and more a hopeful theology. As the Israelites near their destination, it becomes increasingly clear that the manifold challenges they are to face will be considerable. The Israelites could not afford to rely only on recollections of past successes through divine intervention. What the Israelites will need is confidence in the future; knowing that the same God who authored their salvation from the time of their bondage in Egypt can be counted on to reliably continue to protect them. God was there at the beginning of their journey. God will be there as the journey ends.
What was crucial for the Israelites at the time of the conquest of the land is equally important for Jews today. As much as we look back at a remarkable past, we must also look forward to a glorious future.