Monergism is the position in Christian theology that God, through the Holy Spirit, works to bring about the salvation of an individual through spiritual regeneration, irrespective of the individual's cooperation. Monergism is most often associated with Calvinism (such as Presbyterianism and the Dutch Reformed Church) and its doctrine of irresistible grace, and particularly with historical doctrinal differences between Calvinism and Arminianism.
This position contrasts with Armenian synergism: the belief that God and individuals cooperate, to bring individuals salvation.
Lutheranism holds to the soteriological position of monergistic salvation and synergistic damnation, rejecting Calvin's monergistic damnation and Arminius' synergistic salvation; Lutheranism teaches that God predestines some to salvation but does not predestine others to damnation as God wills that all might be saved (1 Tim 2:3-6, Rom. 11:32, etc.). The Scriptural basis for man's justification by faith alone is summarized in the Epitome of the Formula of Concord under Free Will and The Righteousness of Faith, and fully discussed in the Solid Declaration of the Formula of Concord under Free Will and The Righteousness of Faith. Likewise the Defense of the Augsburg Confession discusses the Scriptural basis of man's Justification. Lutherans thus confess that salvation is monergistic, saving faith being the work of the Holy Spirit alone while man is still the uncooperative enemy of God (Rom. 5:8,10), but man's damnation is synergistic - Scripture states repeatedly that man participates in and bears the responsibility for resisting God's grace of the free gift - not enforced gift - of salvation (ex: Matt. 23:37, Heb. 12:25, Acts 7:51, John 16:9, Heb. 12:15, etc.). Thus, you will see Calvinists incorrectly accuse Lutherans of Arminianism and Armenians incorrectly accuse Lutherans of Calvinism. Lutherans view their stance not as having one foot in Calvinism and one foot in Arminianism, but having both feet firmly planted in scripture.