"Have you ever noticed how nobody says, “Oh, my Buddha?” Or how names like “Mohammed” or “Joseph Smith” never get used as bywords? But the name of God, and the name of Jesus in particular, are used as cuss words in almost every culture and language.
Is it just antiquated manners that makes us stop saying this around our grandmother? Or is that pang of conscience rooted in the Truth?"
Old Matthew Henry had this to say about Exodus 20:5
“Thou shalt not take the name of the Lord thy God in vain. It is supposed that, having taken Jehovah for their God, they would make mention of his name (for thus all people will walk every one in the name of his god); this command gives a needful caution not to mention it in vain, and it is still as needful as ever. We take God's name in vain,
[1.] By hypocrisy, making a profession of God's name, but not living up to that profession. Those that name the name of Christ, but do not depart from iniquity, as that name binds them to do, name it in vain; their worship is vain (Matt. xv. 7-9), their oblations are vain (Isa. i. 11, 13), their religion is vain, Jam. i. 26.
[2.] By covenant-breaking; if we make promises to God, binding our souls with those bonds to that which is good, and yet perform not to the Lord our vows, we take his name in vain (Matt. v. 33), it is folly, and God has no pleasure in fools (Eccl. v. 4), nor will he be mocked, Gal. vi. 7.
[3.] By rash swearing, mentioning the name of God, or any of his attributes, in the form of an oath, without any just occasion for it, or due application of mind to it, but as a by-word, to no purpose at all, or to no good purpose.
[4.] By false swearing, which, some think, is chiefly intended in the letter of the commandment; so it was expounded by those of old time. Thou shalt not forswear thyself, Matt. v. 33. One part of the religious regard the Jews were taught to pay to their God was to swear by his name, Deut. x. 20. But they affronted him, instead of doing him honour, if they called him to be witness to a lie.
[5.] By using the name of God lightly and carelessly, and without any regard to its awful significancy. The profanation of the forms of devotion is forbidden, as well as the profanation of the forms of swearing; as also the profanation of any of those things whereby God makes himself known, his word, or any of his institutions; when they are either turned into charms and spells, or into jest and sport, the name of God is taken in vain.