Would Christianity have survived

[Dr. D 792]

Take a look at the handy table on page 7 of the book I quoted and linked,

http://books.google.ca/books?id=HcFSaGvgKKkC&printsec=frontcover&dq=Rodney+Stark,++The+Rise+of+Christianity&source=bl&ots=dib17o-b5r&sig=3XIoDjefvfgqdAEIgznCzwVkS7Y&hl=en&ei=KGbxTO6EAoiznge3leWNCw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCgQ6AEwAg#v=onepage&q&f=false

for AD 300 he has over 6 million Christians. The Edict of Milan was issued in 313.

Unfortunately, pages 7 to 17 are not shown when I open your reference but it does state that Christianity grew at a rate of about 40% per decade and that there were about 1,000 Christians in the year 40. Calculating from there, we could determine that there would be about 40,000 Christians in the middle of the second century which by the standard of Rome's population would not be all that great.