I am sure that we would all agree that saying the word God and putting a profane word behind it is using His name in Vain. Also Just saying Jesus Christ as an exclamation is also using that name in vain. However I think that many who profess Christ use God's name in vain by using it as an exclamation and using letters "OMG." Perhaps this happens because we do not fully understand what it is to be Holy and have a holy name, but I am of the mind-set that any mention of God for any reason other than teaching, learning, or worship is using His name in vain and the same with the Lord Jesus Christ. If we speak or write out the misuse in full or abbreviate it, it is still using His name in vain. Something to think about.