Repentance in its Narrow sense and Broad sense

"The term repentance is used in a narrow sense to signify the knowledge of sin and heartfelt sorrow and contrition. In Mark 1, 15 we read: 'Repent ye and believe the Gospel.' In this statement John the Baptist evidently did not include faith in repentance, otherwise his statement would be tautological. In Acts 20, 21 Paul relates that he had been 'testifying both to the Jews and also to the Greeks, repentance toward God and faith toward our Lord Jesus Christ.'  Since faith is named separately in this text, the term repentance cannot embrace knowledge of sin, contrition, and faith. Likewise, the Lord says concerning the Jews that despite the preaching of John the Baptist they 'repented not afterward that they might believe him,' Matt. 21, 32 . . . . By repentance he refers to the effects of the law and means to say that, since they had not become alarmed over their sins, it had not been possible for them to believe. For there will not be faith in a heart that has not first been terrified." - C.F.W Walther, The Proper Distinction between Law and Gospel