Luther advises worship styles and traditions as mutable and optional

This is my advice: If your lord, the margrave and elector, etc., permits the gospel of Jesus Christ to be preached with purity and power and without human additions and the two sacraments of Baptism and the Body and Blood of Jesus Christ to be administered and offered according to their institution…go along in God’s name and carry a silver or gold cross and wear a cope or alb of velvet, silk, or linen. And if one cope or alb is not enough for your lord, the elector, wear three of them…Moreover, if His Grace is not satisfied that you go about singing and ringing bells in procession only once, go about seven times…If your lord, the margrave, desires it, let His Grace leap and dance at the head of the procession with harps, drums, cymbals, and bells…I am fully satisfied, for none of these things (as long as no abuse is connected with them) adds anything to the gospel or detracts from it. Only do not let such things be regarded as necessary for salvation and thus bind the consciences of men…Only what God commands is necessary; the rest is free.

Martin Luther
Letters of Spiritual Counsel

Luther on stripping ceremonials from the Mass

In the first place, in order that we might safely and happily attain to a true and free knowledge of this sacrament, we must be particularly careful to put aside whatever has been added to its original simple institution by the zeal and devotion of men: such as vestments, ornaments, chants, prayers, organs, candles, and the whole pageantry of outward things… All the rest is the work of man, added to the word of Christ and the mass can be held and remain a mass just as well without them.

Martin Luther
The Babylonian Captivity of the Church

Without the words of the Gospel, everything else in the mass is useless

And now it has finally come to this: the chief thing in the mass has been forgotten, and nothing is remembered except the additions of men! … Indeed, the greatest and most useful art is to know what really and essentially belongs to the mass, and what is added and foreign to it. For where there is no clear distinction, the eyes and the heart are easily misled by such sham into a false impression and delusion. Then what men have contrived is considered the mass; and what the mass really is, is never experienced, to say nothing of deriving benefit from it … If we desire to observe mass properly and to understand it, then we must surrender everything that the eyes behold and that the senses suggest – be it vestments, bells, songs, ornaments, prayers, processions, elevations, prostrations, or whatever happens in the mass – until we first grasp and thoroughly ponder the words of Christ, by which he performed and instituted the mass and commanded us to perform it. For therein lies the whole mass, its nature, work, profit, and benefit. Without the words nothing is derived from the mass.

Martin Luther
A Treatise On The New Testament, That Is, The Holy Mass.

Luther exhorts his flock to private confession

So if there is a heart that feels its sin and desires comfort, it has here a sure refuge where it finds and hears God’s Word because through a human being God looses and absolves from sin….We urge you, however, to confess and express your needs, not for the purpose of performing a work but to hear what God wants to say to you. The Word or absolution, I say, is what you should concentrate on, magnifying and cherishing it as a great and wonderful treasure to be accepted with all praise and gratitude. …

Thus we teach what a wonderful, precious, comforting thing confession is, and we urge that such a precious blessing should not be despised, especially when we consider our great need. If you are a Christian, you need neither my compulsion nor the pope’s command at any point, but you will force yourself to go and ask me that you may share in it. However, if you despise it and proudly stay away from confession, then we must come to the conclusion that you are not a Christian and that you also ought not receive the sacrament [of the Altar]. For you despise what no Christian ought to despise, and you show thereby that you can have no forgiveness of sin. …

If you are a Christian, you should be glad to run more than a hundred miles for confession, not under compulsion but rather coming and compelling us to offer it. For here the compulsion must be reversed; we are the ones who must come under the command and you must come in freedom. We compel no one, but allow ourselves to be compelled, just as we are compelled to preach and administer the sacrament.

Therefore, when I exhort you to go to confession, I am doing nothing but exhorting you to be a Christian….For those who really want to be upright Christians and free from their sins, and who want to have a joyful conscience, truly hunger and thirst already.

Martin Luther
Book of Concord: A Brief Admonition to Confession

Luther did not want to bring schism on the Church

I do not like and I never shall like a schism. Since on their own authority the Bohemians have separated from our unity, they have done wrong, even if the Divine right had pronounced in favor of their doctrines; for the supreme Divine right is charity and oneness of mind.

…I repulse the charge of Bohemianism. I have never approved of their schism. Even though they had divine right on their side, they ought nor to have withdrawn from the Church, because the highest divine right is unity and charity.”

Martin Luther
Debate in Leipzig between Luther and Eck
July 4th, 1519