Surrendering to Krishna: Acting as an instrument

Q. If Buddha and Krishna are the same Person then why is there a contradiction in Their teachings? While Buddha preached non-violence, why does Krishna justify anger and violence?

I have seen that over time, some of the teachings of Buddha have been modified to suit the times. Could the same have happened to Krishna's teachings also?

Q. 1. Is there a difference between Bhakti and Saranagati?

Bhakti is devotion, or service in devotion. Saranagati is the act of submission and surrender.

Q. Part1: This is with regard to 'disliking other devotees' (referred to in a previous digest). Whilst I understand it is possible to forgive a person who has caused physical pain to another person, I have wondered for sometime about the following.