I love this triumphant line from David:
Some trust in chariots and some in horses, but we trust in the name of the Lord our God.
Psalm 20:7, NIV
Israel fought many foes under David and won because the Lord was with them, which was the point of what Moses recorded:
The king, moreover, must not acquire great numbers of horses for himself or make the people return to Egypt to get more of them, for the Lord has told you, “You are not to go back that way again.”
Deuteronomy 17:16
Like I said before, the idea here was to trust in God for provision, not in oneself. This is what led to what many term “The Sin of David” (as if there was only one, lol) which we see in 2 Samuel 24 and 1 Chronicles 22, where David takes a census of his fighting men. Why, if not to prepare for some war against an adversary? This demonstrated an apparent lack of trust in God.
When we come up against foe to big to bear, we shouldn’t take stock of our assets, we should take it to our God. There’s nothing wrong with taking action and trying to do what you are able to, but not until you take it to God and ask Him to lead the way. Doing it our own way without involving God is — at best — benign, but at worst is a road that leads to sin.