Aikido is a martial art for which the strength of the attacker is used against himself.
It is not important whether Jesus was the son of god or not. He supposedly once said: 'if someone strikes you on the right cheek, present the left cheek'. This kind of practice must also be done verbally and mentally.
Reductio ad absurdum
For instance: When someone says: "I despise you", you must answer by: "I admire you, and I'm trying to become like you". This will render the former statement devoid of any sense and it is a good way to channel your the attacker's karma.