The gospel which Jesus preached is a direct challenge to the power structures of this world. We do not often, perhaps, think of it like that. Children of our times as we are, we like to keep politics and religion in separate and watertight compartments. But try selling that line to a Jew of the first century. Or try selling it to a Roman emperor, for whom the worship of the national gods was a vital part of what constituted obedient allegiance to himself!
Religion was woven tightly into the whole social fabric of the world, as it has been at almost all times and almost all places in human history, with only the last two centuries in certain parts of the Western world being exceptions, and even then the split is only skin deep. Result: challenge the religion, and you challenge the society. Summon people to a new allegiance to God, and you weaken their allegiance to Caesar. Or, as it may be, summon nationalist rebels to a new allegiance to God and you weaken their allegiance to the rebel cause, as they discover that their rebellion proceeded not from faith and trust but from fear and bruised arrogance. There you have, in a nutshell, the historical and political reasons why Jesus was crucified.
From The Crown and the Fire by NT Wright. Read in “Bread and Wine: Readings for Lent and Easter“.
I like the way he captures that Jesus’ freedom was a power threat both to the state and to the rebels.