They claim that anger leads to violence and sin. That may be true. But anger does not necessarily lead to violence and sin. Anger can also lead to constructive action to correct the injustice.
They chastise people who call for peaceful protests, claiming that such actions disturb the peace, inconvenient other people. That may be true. But all action to address injustice disturb the status quo and inconvenient some people. Such may or may not be excessive, depending on the strength of such action and the degree of the injustice addressed. Such action may also inform others, encourage others, leading to a stronger movement towards correcting that injustice.
They claim that judgement and anger against injustice is the prerogative of God, not of man or woman. But didn’t God also command us to love justice and hate evil? Didn’t God also call for us to come to the aid of the widow, the orphan, the oppressed? What are we if we are to witness someone in need because of social injustice, someone oppressed by injustice and do nothing, say nothing, as if we are blind?
It may be inadvisable to fight an immensely mighty unjust power with violence for many reasons. Violence itself begets more violence, leaving behind consequences way beyond toppling the unjust power, even if it succeeds. Let alone the tremendous destruction and suffering unleashed in the fighting. It can be argued more suffering results from the struggle, hence it is not worth it. However, non-violent actions shouldn’t be condemned outright.
Prayer for the victims, prayer for those who commit the injustice, restorative action are the least we all can do. Rather than condemning those we disagree with, why don’t we do something positive and constructive? Learn the truth. Live in the truth. Love one another despite all the effort to divide. Be kind to the oppressed. Do not assist the oppressor. Appreciate, if only in confidence, the brave.