I have heard of this question several times and it was brought up again during Pelita’s dialoque meeting last friday.
I guess it is clear that going to church is not compulsory for salvation, that is: you still can be a Christian and not going to church, your salvation is based on what Jesus has done on the cross not on your going to church. Yet the bible does say that we as Christians need to encourage one another especially as the Day is approaching (Hebrews 10:24-25).
I believe there are more arguments to support the importance of Christian gathering (Church) from the bible apart from Hebrews one above. I have read some of very interesting arguments from DB Knox Vol 2. I need to re-read that again and summarise it. Hopefuly when people ask me this question in the future i will be more equipped to answer.