As can be read to the left, I have been an Orthodox inquirer for about a year. I am also a Freemason and in fact, am the master of my lodge this year. I do intend to disclose my membership to my priest, and if he should say that I must demit in order to join the church, I would obey.
However, whenever these discussions come up, I find that they are often based on a bunch of hooey. In my experience, Masonry (at least in the United States) is a fraternal service organization. Far from being deist, it is overly biblical and in fact, Christian. Some facts of note:
* the three Masonic degrees are based on the building of King Solomon's temple
* each of the degrees features readings from the Bible. For example, Psalm 133.
* upon initiation, a new Mason is taught that the Holy Bible is a great light and is told "The Holy Bible is dedicated to the service of God, for it is the inestimable gift of God to man, and the rule and guide to His faith and practice"
* a Holy Bible is placed open upon the table in the middle of the lodge room. The meeting cannot take place if the Bible is not open upon the table.
* every lodge meeting is opened with a prayer that says "you have promised that when three or more are gathered in your name, you will be among them". These are Christ's words.
* every lodge is dedicated to St. John the Apostle and St. John the Forerunner. In fact, the Masonic year begins on December 27, the day of St. John the Apostle.
These are just off the top of my head, but I find the fraternity to be quite Christian.
Now, a word on secrecy. The secrets of Masonry are basically "the secret handshake". Otherwise, things are open. My lodge is a registered non-for-profit corporation, for crying out loud, so of course we would need to open the books for an audit.
I recently explained the "secrecy" to a new applicant. He was worried about what he could ask or what I could tell him. I explained to him, "It is the same as if I were to ask you about the business you run. You would probably tell me about what you do, who works there, how long you have been in business, and that sort of thing. In fact, you would probably tell me pretty much everything I asked. But, I bet you wouldn't let me peek at your bank records or attend a meeting of your board of directors."
Secrecy, by itself, is not bad. Accountants maintain the confidentiality of their client's finances. Husbands and wives do not discuss their marital relations with others. Most people do not discuss their salaries at parties.
In my opinion, if someone is to have an opinion, that person has a duty to make it an informed one. I will answer any question that anyone might have about Freemasonry, if anyone should care to ask.