Melanchthon along with Luther denounced what they believed was the exaggerated cult of the saints, asserted justification by faith, and denounced what they considered to be the coercion of the conscience in the sacrament of penance (confession and absolution), which they believed could not offer certainty of salvation. Both rejected the doctrine of transubstantiation, i.e. that the bread and wine of the eucharist are converted by the Holy Spirit into the flesh and blood of Christ; however, they affirmed that Christ's body and blood are present with the elements of bread and wine in the sacrament of the Lord's Supper. This Lutheran view of sacramental union contrasts with the understanding of the Roman Catholic Church that the bread and wine cease to be bread and wine at their consecration (while retaining the appearances of both). Melanchthon made his distinction between law and gospel the central formula for Lutheran evangelical insight. By the "law", he meant God's requirements both in Old and New Testament; the "gospel" meant the free gift of grace through faith in Jesus Christ.