Originally from here.
Obedience is of two kinds, “have to” and “want to.” The “want to” has its source in the love of the Father, even though no other reward should follow, yea even if the Father should desire to destroy His child. The “have to” has its source in hoping to get paid, or springs from self-love. “Want to” obedience always does as much as possible, without needing to be told to. “Have to” obedience does as little as possible, yea nothing except what is directly commanded. The “want to” is never able to do enough for Him; but he who renders “have to” obedience thinks he is constantly doing too much for Him.
The “want to” rejoices in the chastisement of the Father, even though he may not need chastisement because he has not transgressed in anything. The “have to” wishes to be without chastisement, even though he may do nothing right.
“Want to” obedience has its treasure and righteousness in the Father whom it obeys for the sole purpose of manifesting His righteousness. The “have to” person’s treasure and piety are the works which he does in order to be pious.
The “want to” remains in the house and inherits all the Father has. The “have to” wishes to reject this and receive his legally due pay.
The “have to” looks to the external and to the exact letter of the command of his Lord. The “want to” is concerned as well about the inner witness and the Spirit.
“Have to” obedience is imperfect, and therefore his Lord finds no pleasure in it. “Want to” obedience strives for and attains perfection, and for that reason the Father cannot reject him.
“Want to” obedience is not the opposite of “have to” obedience, as it might appear, but is better and higher. And therefore let him who is obeying because he “has to” seek for the better—the “I want to” obedience. In no way should he have an “I have to do this” attitude.
“Have to” obedience is Mosaic and produces Pharisees and scribes. “Want to” obedience is Christ-like and makes children of God. The “have to” is either occupied with the ceremonies which Moses commanded or with those which people themselves have invented. The “want to” is focused on the love of God and one’s neighbor; yet he also submits himself to the ceremonies for the sake of those who serve because they “have to,” so that he may instruct them in that which is better and lead them to “want to” obedience.
“Have to” obedience produces self-willed and vindictive people; “want to” obedience creates peaceable and mild-natured persons. “Have to” obedience is wearisome and is glad when the job is done. But “want to” obedience is light and directs its gaze to that which endures.
The “have to” is grumpy, deep inside wanting to do his own will; the “want to” would gladly have all men to be as himself. The “have to” is the Old Covenant, and had the promise of temporal happiness. The “want to” is the New Covenant, and has the promise of eternal happiness, namely, the Creator Himself.
The “have to” is a beginning and preparation for happiness; the “want to” is the end and completion itself. The “have to” endured for a time; the “want to” will last forever. The “have to” was a figure and shadow; the “want to” is the reality and truth.
“Have to” obedience was established to reveal and increase sin. “Want to” obedience follows to do away with and eliminate the revealed and increased sin.
The Reason for the Mosaic Law
If a man wants to escape from sin, he must first hate it. And if he would hate it, he must first personally know it. And if he would know it, there must be something to stir up and make known his hidden sin. Now, it is Law or Scripture which does this: for as much as the Law demands, that much more the man turns from God to that which he has done, justifies himself by his ceremonial accomplishments, and clings to them as to his treasure. The greater his love for his accomplishments becomes, the more and the greater will grow his hatred for God and for his neighbor. For the more and the closer a man clings to the creature, the farther he is from God. The more he desires the creature, the less he will have of the Creator.
Moreover the law gives occasion to people to depart farther from God, not because of itself (for it is good), but because of the sin which is in man. This is also the reason why Paul says that the law was given: that it might increase sin, that sin might thereby become known. Yea, the law is the strength of sin and therefore it is just like the “have to” obedience, that is, obedience to law, which leads people into the most intense hatred of God and of one’s neighbor. Therefore “want to” obedience—love—is a sure way through which man escapes from such hatred and receives the love of God and of one’s neighbor. Therefore as one (having to do something) administers death, the other (wanting to do something) administers life. The one is the Old Testament; the other, the New.
“Want To” Obedience Contrasted with “Have To”
According to the Old Testament, only he who murdered was guilty of judgment; but in the New, he also who is angry with his brother. The Old gave permission for a man to separate from his wife for every reason; but not at all in the New, except for fornication [edit:–or desertion, 1 Cor. 7:15]. The Old permitted swearing if one swore truly, but the New will know of no swearing. The Old has its stipulated punishment, but the New does not resist the evil.
The Old permitted hatred for the enemy; the New loves him who hates, blesses him who curses, and prays for those who wish one evil. It also gives alms in a manner that the left hand does not know what the right has done. It says his prayer secretly, without evident and excessive babbling of mouth. It judges and condemns no one. It takes the mote out of the eye of one’s brother after having first cast the beam out of one’s own eye. And it fasts without any outward pomp and show.
The New is like a light which is set on a candlestick and lightens everyone in the house. It is like a city built on a hill, being everywhere visible. It is like good salt that does not become tasteless, being pleasing not to man, but to God alone. It is like a good eye which illuminates the whole body. It takes no anxious thought about clothing or food, but performs his daily and upright tasks.
The New does not cast pearls before swine nor that which is holy before dogs. It seeks, asks, and knocks; finding, receiving, and having the door opened for him. It enters through the narrow way and the small gate, and guards himself from the Pharisees and scribes as from false prophets. It is a good tree and brings forth good fruit. And it does the will of his Father, hearing what he should do, and then doing it.
The New is built upon Christ the chief cornerstone. It stands against all the gates of Hell, that is, against the wrathful judgment of the Pharisees, of the mighty ones of earth, and of the scribes. It is a house and temple of God, against which no wind and no water may do anything, standing secure. Everything which withstands the teaching which proceeds from the New, denying its truth, will itself finally give evidence that the New is where God really dwells—although it is now maligned by the Pharisees and scribes as a habitation of the devil.
Yea, in the end those who obeyed because they “wanted to” shall hear, “Behold, the tabernacle of God is with men, and He will dwell with them, and they shall be His people, and God Himself shall be with them, and be their God,” etc. But of the house of the Pharisees and scribes (who didn’t put their heart in their obedience), it shall be said, “Babylon the great is fallen, is fallen, and is become the habitation of devils, and the hold of every foul spirit, and a cage of every unclean and hateful bird,” etc. But to God be all honor, praise, and glory through His beloved Son, our Lord and Brother Jesus Christ, Amen.
Michael Sattler was a first generation Anabaptist in Switzerland, a prominent leader in the so-called “Swiss Brethren.” After having his tongue cut out, he was burned at the stake for “heresy.” A few days later, his wife Margaretha was drowned. Although the author of this tract is actually not known, many scholars assume that Sattler is the author, from its style and it being associated with the Schleitheim Confession.
 The more literal translation of these phrases is “servile (slavish)” and “filial (sonly or family-like).” However, to make the article easier to grasp, the phrases “want to” and “have to” are used to catch the spirit of what the author was trying to say. A slave obeys because he “has to.” A true son obeys because he “wants to.”
 Here the author is probably referring to the Catholics (Pharisees) with their ceremonialism, and to the Protestants (scribes) with their sophisticated theological emphasis.
 Romans 5:20.
 Romans 7:12
 1 Corinthians 15:56
 Revelation 21:3
 Revelation 18:2