Is grace not cheap if we do not have to work for it?

Luther:

Because He, Christ, has become King and Priest for you and He gives these great benefits to you you are not allowed to think that this has happened freely or that this has cost little, or that these benefits come to you due to your own merits. Sin and death are overcome in Him and by Him for you – to give grace and life to you! However, He has endured much harm for it and it has cost Him much: He had to acquire it with the expensive price of His own blood, body and life.

Because taking away God’s anger, judgement, hell, death and all that is harmful, and acquiring all that is good, could not happen before God’s justice was satisfied – sins are paid and the death is overcome through justice.

Therefore it is customary for the apostle Paul, when he preaches the grace of God in Christ, that he at the same time also speaks about Christ’s suffering and blood. He does that to show that all benefits through Christ are not given to us without an incredible cost and an astonishingly high price.

This is shown when he says: ‘Whom God hath set forth to be a expiation through faith in his blood’ (cf. Romans 3:25). Or: ‘For I determined not to know anything among you, save Jesus Christ, and Him crucified’ (cf. 1 Corinthians 2:2).