The doctrine of Solus Christus (a.k.a. Christ Alone) touched on several debates the reformers had with the Roman Catholic Church. During the Reformation, the Church’s homage to the Virgin Mary and to the Saints was condemned by the reformers, as was the Church’s apparent “works” righteousness.
As the supreme High Priest of His people, Jesus, the reformers argued, was the only Mediator between God and man. To pray to Mary or the saints was not only disrespectful to Christ and His sacrifice, but was flat-out idolatry as well.
As Christ, alone, is the Mediator between God and man, it necessarily followed that any religion that proposed another way to God, apart from Christ, was completely invalid. Christ alone, declared the reformers, is the Mediator—He alone is the Way, the Truth, and the Life—not Mary, the saints, or any other religious figure. To attempt to get to God by any other way was unbiblical and futile.
But the debate between the reformers and the Church on this matter did not stop with matters dealing with traditional customs of worship and prayer. The doctrine of Solus Christus also had much to do with essential matters of faith.
The over-all banner of the Reformation was “Justification by faith in Christ alone.” With such emphasis on penance, indulgences, and faith-plus-works doctrines, the Roman Catholic Church was accused by the reformers as adhering to a doctrine that did not place faith in Christ’s sacrifice alone. A faith-plus-works gospel was “another gospel” to the reformers, or rather no gospel at all. The Church was thus deemed anathema, or accursed, and the reformers felt justified to leave the Roman church to worship with the true, Christ-centered Church.