making your own choice?

Recently Moses's classmate formed a small group called " adventure brothers", Moses is invited to be part of it. It is an idea that the boys can meet twice a month on one Saturday afternoon, and it will take turn for the parents to host the meeting.
There are total 7 boys so far. The 1st meeting was at one of the classmates' house, they played together in their yard, and then hiked together in the park. I like it so much as they can enjoy the nature together.

Last week, it was the 2nd meeting, one of the mom was the host, then she suggested having a Zombie party, kids are required to dress up and make up like a dead man, then they walk together in a park.
When I received the invitation, I feel so uncomfortable. As Christians, I believe that we shouldn't imitate devils, dead men.  At the beginning, Moses was so excited to tell me that they were gonna have 2nd meeting. I immediately told him that I dislike that idea as God doesn't favour this kind of behavior. Then Man said it is hard to reject them, and Moses might have difficulties to get along with people from the other community.

I prayed to God to change the situations during our small group. When it was Saturday afternoon, I asked Moses to be ready to go to that party, He then said to me :" I thought You don't allow me to go ." I said :" since it is a meeting of your adventure brothers, if you really love to go, I can let you go but I won't let you dress up anything like dead person." . Then he replied to me :" I don't want to dress up like dead person, and I also don't want to go. I know what you mean.". I am so glad that he understands so much. At that moment, I strongly feel that Holy Spirit is protecting his heart, and with us. I know when he said "no", he was willing not to go, not forced by me. Since he is old enough to understand more about God,  I have been educating him that he has to make right choices. I know that I won't be with him forever, but when Jesus is inside his little heart, he learns what the good values, good choices are. But when we raise up our children in God's way, I think they won't be so bad when they grow up, even though one day he leaves God, he will return to Him because Holy Spirit is with us forever and forever. As learned from Bible, we cannt lean on the world, we have to lean on God. The world has been changing but God never changes!

Jesus, please protect their hearts.