That is a question that some of you have asked before on this site. One way to answer this question from a Christian perspective is to just look at one of those blood-curdling oaths a Mason is obliged to make and then to compare it to God’s word.
Look for instance at this portion of a Master Mason’s Oath, to be found at Duncan’s Masonic Ritual and Monitor.
“All this I most solemnly, sincerely promise and swear, with a firm and steady resolution to perform the same, without any hesitation, mental reservation, or secret evasion of mind what-ever, binding myself, under no less penalty than that of having my body severed in two, my bowels taken from thence and burned to ashes, the ashes scattered before the four winds of heaven, that no more remembrance might be had of so vile and wicked a wretch as I would be, should I ever, knowingly, violate this my Master Mason’s obligation. So help me God, and keep me steadfast in the due performance of the same.”
These few simple lines speak volumes by themselves in answering the above question, not to mention the fact that swearing any form of oath is expressly forbidden by our Lord.
But I say, do not make any vows! Do not say, ‘By heaven!’ because heaven is God’s throne.
And do not say, ‘By the earth!’ because the earth is His footstool. And do not say, ‘By Jerusalem!’ for Jerusalem is the city of the great King.
Do not even say, ‘By my head!’ for you can’t turn one hair white or black.
Just say a simple, ‘Yes, I will,’ or ‘No, I won’t.’ Anything beyond this is from the evil one. (Mat. 5 : 34-37)
The Lord could hardly have been more clear on the issue. Of course, if you do not take His word seriously you have much bigger problems to worry about than to speculate about whether Freemasonry is evil or not!