I'll go with my Jewish friends here. It is they who will not spell the name of the Lord. As for biblical justification, try the Ten Commandments.
"This command originally intended to prohibit taking false oaths. More than that, it also forbade disrespect shown to God by using his name wrongly or frivolously. God's name was special. It was the nearest the Israelites came to possessing any part of God, and had to be treated with the utmost care. Later Jewish practice takes this prohibition so seriously that the name of God, and even the word God, was never spoken, with phrases such as "the Lord" and "the Name" used in its place, and G_d used in print." (http://www.hope.edu/academic/religion/bandstra/RTOT/CH3/CH3_2B1.HTM)
"Later Jewish tradition" became the seedbed for a great deal of mischief. I avoid the whole game of "telephone," whether talking with a Jew or a Roman Catholic, by going back to the source. In the Hebrew OT the Name "Yahweh" is used about 6,823 times, all the consonants spelled out as with every other title or name of God.
Not only is it positively not "reverent" to refuse to spell the word "God," it is rather a violation of the many urgings in the Bible to call on His name, swear by His name, take refuge in His name, and the like. There isn't the echo of the shadow of the hint of an example in the pages of God's Word itself for this practice. No prophet is depicted as saying, "Thus says yod-wink-wink-he" (or, to Anglicise it, "Thus says the L-wink-R-D"). Quite the opposite.
Further, being a manmade rule, it devolces quickly into silliness. I note it is not practices with names with theophoric elements. Otherwise, I'd have to be called "Dani-l," or we'd have to speak of the book of "Isai-h."
Like all "improvements" on the Word of God, it isn't. In fact, refusing to obey God's calling on believers to use His name leads the wrong way, and calls attention only to the pecularity of the writer, not the majesty and holiness of God.
Dan
BTW, just to offer an additional thought — the mere fact that someone is Jewish no more makes him an expert on the Torah, than the fact that someone is an American makes him a Constitutional scholar.
Dan