Now therefore give me this hill country that the LORD promised me on that day, for you yourself heard then that the Anakim were there, with great and fortified cities. Perhaps with the LORD’s help I will drive them out, as the LORD has spoken.” — Joshua 14:12

Caleb said,'If the Lord is with me, I'll drive them out as He promised'. That's not presumptuous — that's faith. The Lord is your helper, so you won't fear. I'll go in the strength of the Lord God. The effect of righteousness is quietness and confidence forever.