Across the board from clergy to congregants, you will see a variety of ways that people spell God. My personal practice is to write out the name, G-o-d, God. Although, when I was in the 3rd grade, I remember a teacher took off points from an assignment because I “spelled God’s name incorrectly,” when I wrote G-d. When I asked my rabbi at the time about it, he said that there was no need for me to write G-d, I could write G-o-d, though he didn’t think the elementary school teacher needed to be taking off points for such things!
There is no law that prohibits the writing of God’s name in Hebrew or in English. However, there is a law that prohibits the erasure of God’s name in the Hebrew. Deut. 12:3 reads, “Tear down their altars, smash their pillars, put their sacred posts to the fire, and cut down the images of their gods, obliterating their name from that site.” Rashi comments on the obliteration of their names and says that from this text we learn that blotting out God’s name is prohibited (even though the text refers to the non-Israelite gods).
Related to Rashi’s comment, one might ask, what name for God is Rashi referring to?
According to Maimonides’ law code and the Talmud, there are seven different names for God which are of sanctity and must be preserved (in the Hebrew): The Tetragrammaton YHVH, Adonai, El, Eloha, Elohim, Shaddai, Tzvaot.1 If we are to say that God (G-o-d) cannot be spelled out, then we would also need to not spell out, in English letters, the seven names for God I just mentioned — this is quite the ordeal, especially since the original prohibition is only referring to the Hebrew letters.
Not writing G-o-d is what we call “putting a fence around the Torah,” and at some level, it is unnecessary piety. The erasure of the English name is simply not prohibited. I certainly did not claim to be a pious 3rd grader when I wrote G-d on my paper, I had simply seen a Jewish adult do it, so I thought that’s what Jews do.
All this said, you might very well see other people writing G-d, or you may have been writing God’s name this way as well. However you write the name of the Holy One of Blessing, remember that it is not the name itself which is holy, it is belief in that infinite, eternal power in the universe that empowers and comforts us.
1) Hilchot Y’sodeh HaTorah 6:2 and Babylonian Talmud Shavuot 35a and b
Rabbi Rachael Klein Miller