To Participate in non-Muslims religious activities like halloween, Christmas

All Praise to Allah Swt and blessings on Prophet Muhammad peace be upon him His family and companions **What should parents do when their kids go to Public Schools in those countries where schools are eager to celebrate Halloween, Christmas or their other religious celebrations** 1. Should their kids not participate in those activities and tell the teachers that they are not interested or can they do some activities like wearing costumes for Halloween ,trick or treat, decorating Christmas tree? 2. Some Masajid arrange special events in same day for Muslim kids like magic shows and others where they distribute candies so kids dont feel to go for trick or treat activities so is it allowed to do such in premises? 3 . What Islam says about those Muslims who participate in nonmuslims religious activities?