This is a great article on using Greek/Hebrew in the pulpit. Well worth a read.
Finally, you use a knowledge of Greek and Hebrew to explain why the translations are different. Before the ESV was available, I used another translation that was a little freer in its translation philosophy. There were two Sundays in a row where I had to correct its interpretation to make what I thought was the true point of the passage. After the service a new Christian came to me and asked, “Can I not trust my Bible?” Ouch! So here is one of the big no-noes from the pulpit. Do not correct the English Bible. Ever! Never say, “the translators got this wrong.” The damage you can do to a person’s trust in Scripture is unimaginable.
So what do you do it you think a particular translation did get it wrong, while at the same time not holding yourself up as “God’s Anointed” that no mere mortal (i.e., pew sitter) may touch! I think there are ways to do it, and a lot of it has to do with how you say it. Be courteous. Be gentle. Be fair. There is a good chance that the translators with whom you are disagreeing know a lot more than you.
How would you disagree with them if they were in the front row that morning? I think you can say things like, “This is a difficult verse to translate, and perhaps you noticed that the XXX version does it differently than the XXX version.” And since you are the pastor and have a responsibility to lead your flock, tell them what you think and why. Nothing wrong with fair, gentle, disagreement. What is wrong is to move into an ad hominem argument where you cast doubt on the translators’ ability to do their work.
This is where footnotes really come in handy. If the interpretation you prefer is in the footnote, you are home free. You can say something like, “If you look at the footnote on this verse you can see that there is some question on how to understand this verse. My personal preference is to go with the footnote.” This does not make anyone mistrust their Bible, and it encourages them to watch the footnotes for themselves.