What then? If some did not believe, their unbelief will not nullify the faithfulness of God, will it?
First, Paul appeals to the Jewish inheritance of the Law from Moses. Now, he appeals to faithfulness of God. He asks, “what then?” The Jews received the Law and were entrusted with God’s words through the prophets and had in their hearts unbelief both in antiquity during the exile in Babylon and now unbelief in the Messiah that was professed and waited for for thousands of years. So, does the faithfulness of God fail simply because His people failed to believe Him and be obedient to Him? This is the question of the moment and it’s a soul check for his readers. Can the unbelief (disobedience, lack of faith, hardened hearts) of God’s people make void the promises of God? This is to suggest that the finite sins and power of man could somehow prevent God’s providence from coming to pass. The greek word Paul uses to describe “nullify” is “καταργέω-katargeó” which denotes “being of no effect (totally without force, completely brought down); done away with, cause to cease and therefore abolish; make invalid”. Paul’s question causes us to ask, can our sin and disobedience cause His purposes and promises to us fail? Leading into the next verse, Paul gives us a reassuring answer but with conditions of God’s judgement that coincides with His mercy and love.