Question, a serious one

Ok, so knowing that December 25th wasn't Christ's birthday & it's actually a pagan holiday, I do my best to stay away from most of it but I have a family that always pulls me in. This year, now I have a brand new grandson. Is it anti-christian to buy gifts and celebrate the festivities? Not celebrating a pagan God but just being a part of the family??? I honestly love Christmas lights but won't put a tree up because I know what it symbolizes; but also I love that the whole family comes together! I couldn't care less about gifts and Christmas shopping or any of that nonsense but I have a grandson now and I want to spoil him. What is the right thing to do???