God's elect worship and serve Him with willing hearts. We willingly believe, willingly worship, willingly give, and willingly do what we can for the glory of God. It is God Who, by effectual grace, makes us willing; but we are willing servants of the Most High God! Any worship, service, or gifts offered to God that is not done with a willing heart is an adomination to Him.
When man, under the powerful action of the truth of God, takes his place as a sinner, God can, in the exercise of grace, take his place as a Savior. And then every question is forever settled; for the Substitute has answered all the claims of justice, and mercy can flow like a river. What I am saying is that when a righteous God and a ruined sinner meet on a blood-splattered platform, all is settled once and for all, settled in such a way as to perfectly honor and glorfy God and eternally save the sinner. The only proper meeting place between God and man is the point where grace and righteousness meet and perfectly harmonize. Nothing but perfect righteousness could suit God, and nothing but perfect Grace could suit the sinner. But where could that take place? Only in the cross. There it is that mercy and truth are met together, and there the believing sinner finds peace for the heart and conscience.