The affirmation defines the Protestant traditions, Lutheran, Reformed, Presbyterian, Baptist, Methodist, Pentecostal, Anglican, and Anabaptist, against what the Reformers saw as a reliance on human works and merit that had grown up in late medieval piety, including the sale of indulgences that first provoked Luther's public protest. Catholic and Orthodox theology also affirms the primacy of grace, both traditions insisting that salvation begins and ends in God's initiative, but they understand it as enabling a real human cooperation in which grace-empowered works have genuine place and value, so the dispute concerns the relation of grace to human response and to the process of salvation over a lifetime, not a simple contrast of grace against works as such.
The Catholic Church and the Lutheran World Federation issued a Joint Declaration on the Doctrine of Justification in 1999, formally stating that the two traditions now share a common understanding of justification by grace sufficient to remove the doctrinal condemnations each side had historically leveled at the other on this point, though significant Protestant bodies outside that agreement, and some traditionalist Catholics, have continued to question how far the underlying disagreement was actually resolved rather than merely restated in shared language.