500 years ago Augustinian monk Martin Luther nailed his 95 theses on the wooden door of the Castle Church in Wittenberg, Germany. Whilst there were others (men such as John Wycliffe and John Huss) who prepared the way for a return to Biblical Christianity, the Protestant Reformation is usually thought to have begun with Luther’s 31/10/1517 public protest against the sale of indulgences, together with his rediscovery of the doctrine of justification by faith. The Roman Catholic Church had merged together the Biblical doctrines of justification and sanctification. The result was a religion of works which Martin Luther realised could never bring peace, joy and an assurance of salvation.
The good news of the gospel is that by an act of free grace God pardons the sin of the believing Christian and accepts that person as righteous in his sight because the perfect righteousness of Christ is credited to that person by faith alone. This is the doctrine of justification (Belgic Confession Art22-23; Westminster Confession Chapter 11)
After God the Father has justified a person, God the Holy Spirit then works progressive change in the believer making that person more and more in character like Christ. It is this process, in which God’s people are to be actively involved (‘working out that which God has first worked in’), that this sermon focusses upon. This is the doctrine of sanctification (Belgic Confession Art24; Westminster Confession Chapter 13).