The master of more than a hundred thousand arts...

And what need is there for more words?  If I were to list all the profit and fruit God's Word produces, where would I get enough paper and time?  The devil is called the master of a thousand arts.  But shall we call God's Word, which drives away and brings to nothing this master of a thousand arts with all his arts and power?  The Word must indeed be the master of more than a hundred thousand arts.  And shall we easily despise such power, profit, strength, and fruit--we, especially, who claim to be pastors and preachers?  If so, not only should we have nothing given us to us, but we should also be driven out, baited with dogs, and pelted with dung.  We not only need all this every day just as we need our daily bread, but we must also daily use it against the daily and unending attacks and lurking of the devil, the master of a thousand arts.
~BOC, LC, LP, 12-13

The Sacraments awaken and confirm faith...

They [the Sacraments] were instituted to awaken and confirm faith in those who use them.  Therefore, we must use the Sacraments in such a way that faith, which believes the promises offered and set forth through the Sacraments, is increased.
~BOC, AC, XIII, 2

The Law is not kept without Christ...

Therefore, in all our praising of works and in the preaching of the Law, let us keep this rule: The Law is not kept without Christ.  As He Himself has said, "Apart from Me you can do nothing" (John 15:5).  Likewise, "Without faith it is impossible to please [God]" (Hebrews 11:6).  For it is very certain that the doctrine of the Law is not intended to remove the Gospel and to remove Christ as the Atoning Sacrifice.  Let the Pharisees, our adversaries, be cursed.  They interpret the Law to assign Christ's glory to works.  (In other words, they say works are an atoning sacrifice, that they merit the forgiveness of sins.)  Works are always rightly praised in this way: they are pleasing because of faith.  For works do not please without Christ as the Atoning Sacrifice. "Through Him we have also obtained access [to God]" (Romans 5:2), not by works without Christ as Mediator.  Therefore, when it is said in Matthew 19:17, "If you would enter life, keep the commandments," we must believe that without Christ the commandments are not kept and cannot please.
~BOC, AP, V(III), 148-149

On speculating about God's eternal foreknowledge and election...

Our curiosity always has greater pleasure in giving itself to these matters than with what God has revealed to us about this matter in His Word.  We cannot harmonize God's revelation with our reason, which we have not been commanded to do anyway.

There is no doubt that God foresaw before the time of the world, and still knows, exactly, which people who are called will believe and which will not believe.  He also knows which of the converted will persevere and which will not persevere.  He knows which will return after a fall and which will fall into stubbornness.  He also knows the number of how many there are on either side.  Beyond all doubt this is perfectly known to God.  However, God has reserved this mystery for His wisdom.  He has revealed nothing to us about it in His Word, much less commanded us to investigate it with our thoughts.  Instead, He has seriously discouraged us from that.  Therefore, we should not reason in our thoughts, draw conclusions, or inquire curiously into these matters, but we should cling to His revealed Word, to which He points us.

~BOC, FSD, XI, 53-55

The giving of Jesus Christ and the Holy Spirit...

Christ was given for this purpose, that forgiveness of sins might be bestowed on us for His sake.  He was also given so that the Holy Spirit might bring forth in us new and eternal life and eternal righteousness.  Therefore, the Law cannot truly be kept unless the Holy Spirit is received through faith.  So Paul says that the Law is established through faith, and not made useless, because the Law can only be kept when the Holy Spirit is given.
~BOC, AP, V (III), 11-12