I would respond with an equally important question: Is God’s call to holiness and obedience of the law sincere to those who He knows cannot heed such calls?
Of course it is sincere. And there will never be a sinner who desires to repent and come to Christ who finds himself unable to do so–because without God’s grace in the first place, he has no desire to repent.
This is a common straw-man, based on a misunderstanding of what spiritual death means. Man is dead in trespasses and sins (Ephesians 2:1-3). Those who disobey God’s command do so because that is what they desire due to their nature. The truth is that God does not have to force any man to remain in his sins and refuse Christ. The opposite is true: without the drawing of the Father, man will continue to refuse (John 6:37-44).
This very question is what Paul anticipated in Romans 9 when he said, What shall we say then? Is there unrighteousness with God? God forbid. Is God unrighteous and unjust because He has chosen to mercy some and not others? No, He has done what He will for His eternal purpose. And again in verse 19: Thou wilt say then unto me, Why doth he yet find fault? For who hath resisted his will? In other words, “Since God has not enabled an individual to respond in faith and repentance, is He not unjust since He has commanded something that the individual cannot do?” Paul’s response is to rebuke us for replying against God.
It is not for us to reason how it works together. We must recognize that we serve a holy, righteous, just God, and that He will do what is best.
Soli Deo Gloria.