What was Martin Luther's fundamental religious problem?

Answer 1

Luther's fundamental religious problem was that early in his career as a monk/priest because the church state that monastic life was the best hope anyone had of salvation. Though despite being very disiplined in the ways of the church he still felt like a sinner. Luther discovered that the penitential cycle intensified rather that quelled his fear that he was damned.

He solved this when he realized that forgiveness from sin resulted from faith alone. Jesus already died for all our sins, so therefore "good acts" do not save only faith does. He also stated all people are priests and went away with sacraments. His 95 theses also addressed how the catholic church was wrong as he only maintain two of the seven sacraments of the catholic church: baptism and the Holy Communion