The Pentateuch and the Book of Joshua have a lot of good things to say about Caleb. According to Numbers 13-14, he was one of the people who spied out the Promised Land in the time of Moses. While most of the other spies were afraid of the giants and tall fortifications in the land, Caleb was undeterred. He told the Israelites that they could take it over, despite the strength of the enemy, for God was on their side. Because the Israelites gave in to panic, God condemned them to wander in the wilderness for forty years. There, they would die, without ever entering the Promised Land. God promised that Caleb, on the other hand, would enter and possess it, for he followed God wholeheartedly.
In Joshua 14-15, Caleb, now an old man, is about to take his possession. He feels as strong as he did forty-five years earlier, when he first spied out the land. Even in old age, he is unafraid of the giants and high walls of Canaan. Inspired by the promise of God, he goes into Hebron and takes it for himself.
What is interesting is that Caleb is not even a full Israelite, for he is the son of Jephunneh, a Kenezite (Numbers 32:12; Joshua 14:6). The Kenezites came from the line of Esau (Genesis 15:19; 36:11, 15, 42), and they eventually associated themselves with Judah (Numbers 13:6).
Why does the Hebrew Bible present the heroic deeds of someone who is not a full Israelite? For many Christians, the importance of Gentiles in the Old Testament foreshadowed the time when God would include them in his new covenant. In the New Testament, God invites the Gentiles to become full members of his covenant people, without the requirement of circumcision. While the Hebrew Bible emphasizes God's relationship with a specific nation, physical Israel, the new covenant creates a new community, in which Jews and Gentles are equal participants. For a lot of Christians throughout history, the presence of righteous Gentiles in the Old Testament indicated that God would one day allow the Gentiles to become a part of his people, without joining physical Israel through circumcision and Torah observance.
As a Christian, I do not thoroughly dismiss this claim, for the Hebrew Bible seems to suggest that even a Gentile can have a relationship with God and experience God's favor. Besides Caleb, Rahab and Naaman the Syrian are good examples of this theme. At the same time, from a scholarly perspective, I'd like to understand the Hebrew Bible on its own terms. The historical-critical method tries to interpret the biblical writings in terms of how they spoke to their original historical contexts. That means that there are other ways to approach the Hebrew Bible than projecting Christian beliefs onto it. And one of those ways is to read the biblical stories in light of themes that appear in the Hebrew Bible itself.
So could there be other explanations for the Hebrew Bible's admiration of Caleb, a Gentile? A possible agenda of the biblical authors was to account for their present reality. Descendants of Caleb occupied Hebron as late as the time of David (I Samuel 25:3; 30:14), and the biblical authors perhaps wanted to explain how they got there. They couldn't say that they were Canaanites because the Calebites had a strong connection with Israel and her god. And they couldn't say that they were full-fledged Israelites because the Calebites understood themselves as Kenezites. Therefore, they included a story about Caleb getting land in Canaan as part of the Israelite invasion.
Biblical authors may also want to valorize Caleb and other Gentiles to make the Israelites look bad. Their goal was not to imply that the Gentiles would replace the Israelites as God's chosen people, however, but rather to shame the Israelites into doing the right thing. "Even these non-chosen Gentiles follow me better than you do, O Israel, my very chosen people," the biblical authors can envision God saying. "You should be ashamed of yourselves. Repent!"
And, even in the Hebrew Bible, there is a stream that encourages the Gentiles to worship the God of Israel. It occurs throughout the Book of Psalms and in the Book of Isaiah. And Solomon's dedication of the temple says, "Likewise when a foreigner, who is not of your people Israel, comes from a distant land because of your name--for they shall hear of your great name, your mighty hand, and your outstretched arm--when a foreigner comes and prays toward this house, then hear in heaven your dwelling place, and do according to all that the foreigner calls to you, so that all the peoples of the earth may know your name and fear you, as do your people Israel, and so that they may know that your name has been invoked on this house that I have built" (I Kings 8:41-43 NRSV). So the emphasis on Caleb's valor may have reminded Israel of her role as a priest to the nations. Perhaps it encouraged Gentiles to worship the LORD. Or it might have assured resident aliens within Israel that they could do great things, even if they were not Israelites by birth.
Christians can read the biblical stories about righteous Gentiles in light of their beliefs concerning God's overall plan, namely, to include the Gentiles as part of the church. But the righteous Gentile can also play a part in the Israelite ideologies of the Hebrew Bible. There, physical Israel has a significant role in God's activity.