I have a Ph.D. in New Testament studies, and from time to time I teach basic Biblical Greek to seminary students. Every time, I rattle off the following spiel:
"Why study Biblical Greek? It's a lot of work, and if you spend your entire life studying you might, just maybe be as proficient as a dock-side worker in Athens around 100AD. Some of you may think "it's a requirement", but that just leaves us wondering why it's required. Some of you are enthusiasts, and have heard pastors say "but the Greek really says" too many times. You probably think that learning Greek will solve all your exegetical and theological problems. But ... well, I hate to break it to you, but it won't.
The best reason to study Biblical Greek is very different. The best reason is that it teaches you to open your Bible with fear and trembling. This is precisely because, much of the time, the Greek doesn't really say. Greek, like English, is sometimes vague and often contradictory. Sometimes, we know exactly what is meant by a word or phrase or sentence or passage. More often, there are still significant questions.
Take "faith in Jesus." Many of you regard that as the center of our faith. But even that might be questioned to someone who really knows Biblical Greek. Does "pistevou tou Christou" mean "faith in Christ" or the "faithfulness of Christ"? The reality is that we don't really know, and it might even mean BOTH.
So, why study Biblical Greek? To learn that you are ignorant on a great many things, and will remain so. It is, as Paul often says, a mystery."
(From memory and past my bedtime, so pardon that I didn't dig up my notes.) We then fall into class discussion. I usually lose about 1/4th of the class the first day.