The Necessity of Dependence and Non-Dependence

Sometimes I encounter a word so good that I have to share it immediately. This happened while reading through The New International Commentary on the Old Testament: The Book of Isaiah Chapters 1-39.

If ever Israel is to become the servant nation, through whom God chose to manifest himself to the world (2:2-5; 12:4-16; 43:8-21; 60:1-3), then the most basic truth she must learn is that God can be trusted, whereas the nations cannot. If she continues to refuse dependence upon God, while attempting to depend on the nations, then she has neither message nor hope. But is she has indeed encountered a God who is greater than all the nations combined and who can, in fact, be depended upon in every situation, then she has something to declare. This is the issue introduced in ch. 7 and carried on through ch. 39: Will Israel recognize that to depend upon the nations is to lose her distinct mission to them, whereas refusal to depend upon them is to become a blessing to them? Until a person or a nation is convinced of God's complete trustworthiness, they cannot lay aside the lust for their own security and become God's servant. (page 194, italics mine)

If this is true of Israel, who had not the Holy Spirit like the church post ascension, how much more true is it of today's church?