Christmas trees are quite safe in the home if you follow a few simple common sense guidelines starting with a fresh cut before bringing it in the house:
First and foremost, no lit candles on the tree-ever! A huge risk is the candle falling off the tree onto the Christmas wrapping below.
Second, be sure to keep it away from drying heat sources. Keep water in the stand at all times. Consider placing a humidifier under it. We know of one family that keeps a Blue Spruce fresh from Thanksgiving to New Years by placing a humidifier in with the presents. It would be in the room anyway, so why not directly under the tree.
Third, consider switching to LED lights. In addition to using less energy, they give off virtually no heat.
Fourth, especially after Christmas, don't leave a lot of loose combustible wrapping materials under the tree. The popular Christmas bags, with a lot of loose tissue paper sticking out the top, are effectively a torch if somehow ignited.
Finally, apply the snap test. If the needles snap in half instead of bending, it's time to remove it. With a fresh cut, well watered tree this shouldn't occur until after the holidays.
With these simple precautions, you can safely enjoy your tree throughout the holidays.
Bear in mind that Christmas trees often get a bad rap in the media. They do not spontaneously combust and start a fire any more then your curtains, drapes, or bedding can spontaneously combust and start a fire. Christmas trees don't cause fires any more than cars cause the drunk driver to crash. There always must be an external factor of some sort.
Moreover, a fresh tree does not burn.
A couple of years ago Jay Leno showed a video clip where a fireman was attempting to demonstrate for a TV news program how explosively a Christmas tree could burn. The fireman must have had a fresh one because he could not get it to ignite with a propane torch. After repeated attempts, he then doused it with gasoline (fortunately the video camera was still recording) and only then was able to get the sensational footage he was after.
A few years back, one of the Christmas tree journals showed photos of a living room gutted by a fire. The Christmas tree had just been put up. It was blackened, but still stood unburned. Everything else, curtains, furniture, was totally destroyed.
That said, remember that while a fresh tree won't burn, a dried out one will most definitely burn if ignited by some source. So follow the above steps to keep your tree fresh as long as possible and then remove it when it fails the snap test.