The primary requisite for a salutary knowledge of the Holy Scriptures is the correct understanding of the distinction between Law and the Gospel. The Bible is full of light to every one who has this knowledge. Wherever this knowledge is lacking, all Scripture remains a book sealed with seven seals.

Walther, C.F.W. The Proper Distinction Between Law & Gospel, p. 60

Comment: Law & Gospel are the two main teachings of the Bible. When a preacher doesn't understand their use, Scripture ends up twisted and confuses the faithful concerning what we can do and what God has done and why.

We seem to engage in a rhetoric of hate. At least, that’s how many on the outside view it. “Yes, God is love,” they might want to agree, “but then you Christians don’t appear very godlike.”

Why do so many think that Christians preach hate? Is it that we shout so loudly and incessantly about what’s wrong with the world that we drown out the still, small voice that tells how Christ has made the world right with God?

Baumler, Gary P. When Christians hurt the cause of Christ, p.
October 2005. Forward in Christ – Editorial, Vol. 92, No. 10

Comment: The Law without the Gospel offers no hope. The Law is the perfect model of love (which we daily fail). The Gospel is the incredible act of God's mercy carried out for us, inspiring us to live the Law of love. Though the selfishness and misdirected love of this world must be denounced, the stronger message of Christianity is that there is forgiveness to be found in the Son of God, who made the ultimate sacrifice to save us.

The law demands and disappoints. Perfection is what it expects of us. We perjure ourselves if we say we have it. The gospel declares and delights. It is God’s declaration of innocence, his Son’s and ours, too, through him. Here is sheer delight, unearned and unending pardon and peace.

Gurgel, Karl R. Doctors all, p. 32
October, 2004. Forward in Christ – From the President’s Office, Vol. 91, No. 10

“Legalism” is a broad term that refers to some misuse of the law. It may refer to identifying morality with strict obedience of legal codes (aside from inner motives), using law to motivate people to modify their behavior, or assuming that obedience to law gains divine favor. In Christian circles it usually expresses itself with a blending of “obedience” to gospel and law.

“Moralizing” is a term used for one aspect of legalism, that of teaching people to be or do good by the threats or promises of law.

Bivens, Forrest L. Getting the Right Message Out –
And Getting It Out the Right Way
Spring 2004. WLQ, Vol. 101, No. 2, p.117

Comment: Both Legalism and Moralizing are a misunderstanding of the purpose, power, and use of the law and gospel.

This is our greatest certainty, that we know where our sins are laid. For the Law lays them upon our conscience, but God takes them and lays them upon the shoulders of the Lamb...

...Sin has only two places where it can be: it is either with you, so that it lies on your shoulders, or it lies upon Christ, the Lamb of God. If it lies on your back, you are lost, but if it lies on Christ, you are free and blessed. Choose then, and take whichever you desire...

Luther, Martin. John 1
cited in: January/February 2005. Preach the Word – You Can Print That, Vol. 8, No. 3, p. 4