Christians what did god mean (mark 6:11)?

And whosoever shall not receive you, nor hear you when ye depart thence, shake off the dust under your feet for a testimony against them. Verily I say unto you, it shall be more tolerable for Sodom and gomorrha in the day of judgement, than for that city. What did he mean when he said "it shall be more tolerable for those cities on the day of judgement"?