Why is the Christmas tree a Christmas symbol?

Many people believe the Christmas tree tradition to be relatively new, brought from Germany by Prince Albert, consort of Queen Victoria. However the fir trees' relationship to Christianity goes much further back to the days of St.Boniface over a 1000 yrs ago. It is said that St.Bonifice, who converted the Germans to Christianity, came across a group of pagans worshipping an oak tree and became so angry that he cut it down. He was amazed as from beneath its roots a small fir tree began to grow, and he took it as a sign of Christianity. However it wasn't until the 16th century the trees were brought inside.