Valid change
"Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves." Romans 13. 1-2
Thomas More was and remains an anachronism, remnant of a bygone communitarian age, out of step with the spirit of individualism unleashed by the Enlightenment and Reformation. It is not that More was a feeble sycophant. His willingness to pay the ultimate price, when the time came to dig his heels in, is testament to his moral and physical courage. It is simply that, for More and those he represents, the way to build and protect a just society is to get involved in the messy business of public life and work through its established mechanisms - but never to take the law into one's own hands, however justified or outraged one might feel.
It would appear that More based his convictions on the the teaching of Paul in Romans 13 and on that of Peter in his 1st letter, chapter 2, verses 13-17. Their similarity suggests they both drew upon the same source, perhaps Jesus remark about "rendering unto Caesar" recorded in Mark 12. 17? Of course Jesus goes on to add ".. and to God what belongs to God", which is what led to More's costly refusal to endorse his earthly boss's usurpation of authority over the Church in England. That would have meant contravening Jesus' command that the unity of his Church should not be broken.
Though it goes against the grain of our individual rights-driven age, we can perhaps understand More's argument in favour of working through the system to effect change as being the better way to preserve public order. But what happens when the law of the land challenges the commandments of God or the instructions of Jesus? This is a dilemma faced by our persecuted sisters and brothers (360 million of them!) every day. It is a vexed question requiring both wisdom and courage.
Another apostle, John, was inspired to write his Revelation to steel the Church's resolve against just such a scenario. But let us be clear, he was not inciting civil disobedience for the sake of individual conscience or the right to live as one pleases. He was equipping the Church to fight for survival in order to remain salt and light in a society which needed it more than its despotic leaders could appreciate. It is on account of such despotic leaders that international law can only ever be provisional... Is that not another example of how the Gospel really is the hope of the world?