Dependence Upon God
When the Israelites wanted a king "like all the nations" (1 Sam. 8:4-5), the problem was much deeper than the name by which they would call their ruler, or the form of government. Moses had told them the time would come when they could have a king (Deut. 17:14-20); but it was to be one whom God would choose (v.15) and he would be the means for God's rule over them (1 Sam. 12:12-15). Their basic sin was lack of dependence upon God.
The same fault was apparent with regard to the Jew's chosen status. In Romans 9 Paul points out that Ishmael and Esau were also descendants of Abraham, but Isaac and Jacob were chosen — wholly dependent upon God. The lineage of Christ was God's business — and arguing with Him was like clay arguing with the Potter.
Paul then asks, "What if God..." chose to show mercy to Gentiles as well as to Jews. "What if God..." made Christ the testing stone — so that He saves those who accept Christ, and rejects those who reject Christ. It is His business; who are we to complain? This chapter does not teach particular election. It emphasizes our dependence upon God. He provides the means of our redemption — the crucified Christ — that will save those who put their trust in Him.
Salvation is a gift of God (Eph. 2: 8), something promised. (Check multi-uses of "promise" in Gal. 3; 4:21-31) A "promise" is a statement of intent which prompts expectation and hope. The Jews failed to please God when they forgot their dependent position and acted as if God owed them honor. We will likewise fail to please God if we forget our constant dependence upon Him and His gift, and begin to act as if he owed us something.
We are to beseech Him for daily bread (Matt. 6:11) and be not anxious for other needs (vs. 31-34). We may cast all our care upon Him (1 Pet .5:67) but this requires that we humble ourselves "under the mighty hand of God, that He may exalt you in due time." There is no room for demands. We come before God as sinners, unworthy; "Just as I am, without one plea, but that thy blood was shed for me." Without Him, we are nothing.