These quotes in Martin Luther are in order by date.
Of course, I just started collecting these on October 19, 2009.
His herculean labor in translating the Bible forced him into a closer familiarity with the original languages, though he never attained to mastery. As a scholar he remained inferior to Reuchlin or Erasmus or Melanchthon, but as a genius he was their superior, and as a master of his native German he had no equal in all Germany. … He studied with all his might and often neglected eating and sleeping. (History of the Christian Church, Vol. VII, ch. 2, sec. 27)
There are various types of mysticism, orthodox and heretical, speculative and practical. Luther came in contact with the practical and catholic type through Staupitz and the writings of St. Augustin, St. Bernard, and Tauler. It deepened and spiritualized his piety and left permanent traces on his theology. The Lutheran church, like the Catholic, always had room for mystic tendencies. But mysticism alone could not satisfy him, especially after the Reformation began in earnest. It was too passive and sentimental and shrunk from conflict. It was a theology of feeling rather than of action. Luther was a born fighter, and waxed stronger and stronger in battle. His theology is biblical, with such mystic elements as the Bible itself contains. (History of the Christian Church, Vol. VII, ch. 2, sec. 28)
Luther … considered himself a good Catholic even in 1517, and was so in fact. He still devoutly prayed to the Virgin Mary from the pulpit; he did not doubt the intercession of saints in heaven for the sinners on earth; he celebrated mass with full belief in the repetition of the sacrifice on the cross and the miracle of transubstantiation; he regarded the Hussites as "sinful heretics" for breaking away from the unity of the church and the papacy which offered a bulwark against sectarian division. But by the leading of Providence he became innocently and reluctantly a Reformer. … Had he foreseen the separation, he would have shrunk from it in horror.
He was as much the child of his age as its father, and the times molded him before he molded the times. (History of the Christian Church, Vol. VII, ch. 2, sec. 28)