2 Now the angel of the Lord came up from Gilgal to Bochim. And he said, “I brought you up out of Egypt and led you into the land which I have sworn to your fathers; and I said, ‘I will never break My covenant with you, 2 and as for you, you shall make no covenant with the inhabitants of this land; you shall tear down their altars.’ But you have not [a]obeyed Me; what is this you have done? 3 Therefore I also said, ‘I will not drive them out before you; but they will [b]become as thorns in your sides and their gods will be a snare to you.’” 4 When the angel of the Lord spoke these words to all the sons of Israel, the people lifted up their voices and wept. 5 So they named that place [c]Bochim; and there they sacrificed to the Lord.
6 When Joshua had dismissed the people, the sons of Israel went each to his inheritance to possess the land. 7 The people served the Lord all the days of Joshua, and all the days of the elders who [d]survived Joshua, who had seen all the great work of the Lord which He had done for Israel. 8 Then Joshua the son of Nun, the servant of the Lord, died at the age of one hundred and ten. 9 And they buried him in the territory of his inheritance in Timnath-heres, in the hill country of Ephraim, north of Mount Gaash. 10 All that generation also were gathered to their fathers; and there arose another generation after them who did not know the Lord, nor yet the work which He had done for Israel.
And now we see why they couldn’t completely drive out the inhabitants, but ultimately this would become part of God’s plan. It’s a demonstration to us, even today, of the fact that we need God to become who He planned for us to be.
We can’t do it on our own strength, because we are no different than the “ancient” Israelites. We are mankind, broken, sinful, and weak. But we are also mankind, loved by God. When we choose Him, we choose to become more like Him, and He enables us to achieve it, slowly, we take on His goodness, we learn to obey, and become stronger with each step.