Oops !! Okay on one occasion he did lose his temper and bear arms...
We worship Lord Krishna and claim that Pandavas vs Kauravas was a good vs evil battle, but there is a lot of doubt in my mind about the truth in the statement. True, Dushasana had tried to disrobe Draupadi at the behest of Duryodhana , but what we tend to ignore is how her husband Yuddhishtira was such a gambling addict that he traded his wife Draupadi in a game of dice. True, Duryodhana had refused to give back Pandavas the land after they returned from exile, but why would he , they had lost it to his maternal uncle Shakuni in a game of dice. True, he had locked Krishna's son Samba in a jail, but Samba did try to abduct Duryodhana's daughter Laksmana. I believe all of these acts were righteous and there was not an ounce of cheating done here.They say "Everything is fair in love and war" but there are some things which was very (if I may say so) 'ungodly' of Lord Krishna. Hiding the sun to let Arjuna kill Jayadratha was (let us say) pardonable, but to guide the Pasthupatastra arrow so that his head falls directly on his father's lap is a blatant foul in terms of the norms of the battle. Jayadratha's father then gets up as he is startled, letting his son's head touch the ground and by his boon (He gave his son a boon that whosoever would let his son's head fall to the ground would immediately have his head burst into 100 pieces) Jayadratha's father's head bursts into a 100 pieces instantly killing him.
Breaking Duryodhana's leg was another such instance where Lord Krishna, going against mace fighting rules lets Bhima attack Duryodhana below the belt to secure a victory for the Pandavas. On seeing this when Balarama decides to kill Bhima for playing unfairly, Krishna goes and calms him down. Some people promote his decision saying that Duryodhana deserved it, but last I checked this is actually called 'cheating'.
Some, even blame him for the death of Ghatotkacha. It is said that he forced Yuddhishtira to unleash this rakshasa son of Bhima so as to force Karna to use his Indrastra which he had been saving for Arjun. In this way, Krishna ensured that Arjun never fell to Karna and even managed to make Kunti persuade Karna to give her his protective kavach-kundal (armor) so as to make him even more vulnerable.
However even after all this, I still respect Lord Krishna as he knew about the various boons and curses possessed by various individuals. He knew the art of neutralizing a given divine weapon to cause their downfall. The epic is truly the tale of how Lord Krishna's vision led him to force some decisions in the camps which would later come back to haunt the Kauravas. After all, he did ensure the victory of the Pandavas even with a smaller army .