It is important that we know and understand the word of God. We should read and study His word on a daily basis.
As worship leaders, it is just as important that we continue to be a skilled musician or singer. For example, David appointed musicians who were skillful. That doesn't mean a degree in music is needed; but bad notes and out-of-tune singing should be avoided as much as possible. Poor music quality is a distraction and hinders people from worshipping.
Too many Christian musicians act as if they are so spiritual they don't need to work on their skills or practice their songs. We need to attempt to play our best for the King of Kings.