Numbers 33:55-56
But if you do not drive out the inhabitants of the land, those you allow to remain will become barbs in your eyes and thorns in your sides. They will give you trouble in the land where you will live. And then I will do to you what I plan to do to them.
God knew that the inhabitants of Canaan had lived their lives against the good that God desires for His creation, and embraced darkness and evil instead. So God chose one particular nation to have His actual "rule book" to explain how to live in accordance with how God designed life to work in this world. He wanted this nation to be the example to teach other nations His goodness and how He prospers those who live in accordance with His ways. So He warned them, that if they allow these pagans to remain among them in the land, then they would learn their errant ways and do the things that bring destruction.
God always provides His Word for us to learn His ways, and whenever anyone, Hebrew or not, pays attention to Him and obeys His rules, then they will be sowing good seed in their lives, and reap the benefits and bountifulness God designed into His creation, and God gets the credit. But anyone who refuses His ways, or ignores His rules, doing something else instead; they will not be aligned with the way God designed this world to work, and will suffer the consequences of their poor choices. They will reap disease (dis-ease), poverty and brokenness.
Even so, come, Lord Jesus!
