On Greek, Lexicons, and the LXX
It should be a truism that knowing Greek (or at least being familiar with it) is useful for preachers. I would go further and say that it is necessary for a long term ministry because knowing the Scripture in the original gives allows the preacher to explain the Bible not only in terms of his or her experience of obeying Jesus, but by genuine descriptive knowledge of its contents. Both kinds of knowledge are important.