There have been many Christians who have courageously followed Jesus' teaching and example over the last two thousand years, but these two Catholics have just caught my eye:
Franz Jägerstätter was an Austrian conscientious objector during World War II. At the time he was criticized by his countrymen, especially Catholics who had served in the military, for failing in his duty as a husband and father. Jägerstätter was sentenced to death and executed in 1943, aged 36.
If you think this sort of thing could never happen in the US or UK, think again...
Ben Salmon was an American conscientious objector and outspoken critic of Just War theology. During World War I the Catholic Church denounced him and the The New York Times described him as a "spy suspect." The US military (which he never joined) charged him with desertion and spreading propaganda, then sentenced him to death (this was later revised to 25 years hard labour).
For more on Ben Salmon see here and here.