hmm

how do you define "taking the lords name in vain"?

because I can tell you saying something like "oh my god" or "for gods sake" is not what that means. When the Bible refers to taking the lords name in vain it means using God to justify wicked means.

Good example being the Spanish conquistadors. Killing and destroying in the name of God and Christendom. "God says those people are wicked and must be cleansed and die". THAT is taking the lords name in vain.

Taking the lords name in vain also means using God to justify a lie. "I swear by God that this is true" when you know it's not true, THAT is taking the lords name in vain.

These are sins.

Saying "oh my God"is not a sin or even taking his name in vain, it is a mere expression.