The roman Catholic church, in the time of the reformation, had a spiritual foundation on a false gospel. Martin Luther is an example of what a Gospel that give counts on man's merit will produce; a man busy with every false hope. When Luther studied scripture and found the truth that salvation is a product of faith alone, his heart was relieved and joy filled every crevice of doubt. The Latin phrase Sola Fide, was a war cry from the reformers who were fighting for the Good News.
Sola Fide: the belief that man is justified, unto salvation, by faith alone...apart from works.
Why was this important?
It is easy to hear when you talk with people about what they believe, that we humans have inflated views of ourselves. We tend to believe that the world revolves around us and that God created this world for our pleasure. Without knowing it, we sometimes even put faith in our own selves.
Sola Fide flies in the face of anyone who thinks they can trust their own actions or law keeping to merit them the favor of God. We are offered forgiveness based on the merit of Jesus' sacrifice on the cross of Calvary. Trusting this promise, and placing our faith solely in the work of Christ is the only way to find salvation.
This is important, because if we allow our own works to have part in our salvation, we are in danger of believing a damning false gospel.
How does it affect us now?
Even the church goers who have a comfortable understanding of the reformer's doctrine of Sola Fide, will still struggle to add something to their salvation. A strong stance on Sola Fide will, in theory, help keep our worship pointed in the right direction; toward Christ, and Christ alone.