The Oneness of Humanity was exaggerated to such an extent by Abdul Baha that he even gave orders to be kind to tyrants, oppressors, and traitors:

Be kind to the human world and be kind to all humans. Treat strangers like friends, and caress outsiders like companions. See enemies as friends and consider demons as angels. Deal with betrayers with utter kindness as you would with the loyal. Make bloodthirsty wolves smell the scent of musk like gazelles. Give traitors shelter and refuge and be the reason for peace of the heart and soul of the anxious.
Abdul Baha, Makatib, vol. 3, p. 160.

Apply ointment to the wounds of tyrants and heal the pain of oppressors. If they give poison, give them honey. If they give swords, give them sugar and milk. If they insult, reply by assistance.
Asad-Allah Fazil Mazandarani, Amr wa khalq, vol. 3,p. 228

Being kind to humans, dealing with strangers like friends, and caressing outsiders just as one would with their companions may be justifiable, but with what logic and reasoning can one justify seeing enemies as friends, considering demons to be angels, dealing with betrayers like loyal people, approaching bloodthirsty wolves like gazelles, and sheltering traitors?

Thus, all criminals, murderers, thieves, and felons should have no fear, for in the Baha段 creed they are all good people who deserve kindness as a reward for their acts.

These orders were so unreasonable and illogical that when Abdul Baha was not preaching the Oneness of Humanity he would often openly contradict them:

If he exercises his anger and wrath against the bloodthirsty tyrants who are like ferocious beasts, it is very praiseworthy.
Abdu値-Baha, Some Answered Questions, p. 215.

Kindness cannot be shown the tyrant, the deceiver, or the thief, because, far from awakening them to the error of their ways, it maketh them to continue in their perversity as before.
Abdul Baha, Selections From the Writings of 羨bdu値-Baha, p. 158

To sum it up, when Baha段 leaders preach Baha段sm they cry out, "Heal the pain of the oppressors. If they give poison, give them honey." But when it is time to practice these beliefs they say, "One cannot be kind to a tyrant, traitor, or thief, for kindness will make them revolt." When they themselves have power, the smallest rights of human beings like freedom of speech are neglected and Baha置値lah gives the order to hit an innocent man in the mouth for uttering a few simple words or those who voice anything against the UHJ are shunned and excommunicated.

It is up to you to draw your own conclusions!

• Oneness of Mankind: Introduction
• Is Oneness of Mankind a New Principle?
• Did the Founders of Bahai Faith Practice Oneness?
• Bahaullah's Attitute towards his Brothers and his Followers
• Bahai Treatment of Covenant Breakers
• Bahai Treatment of Thieves and Some More...
• Two Examples of Bahaullah's Treatment of Non-Bahais
• Is this Principle Correct from a Rational and Logical Perspective
• Contradictions and Conclusions

The articles have been based on the book "Avaze Dohol" - the Beating of the Drum by Masoud Basiti, Zahra Moradi.