Often I see Christians, including well-known teachers, prove their theological views by quoting some famous "great" Christian of the past. Their thought seems to be, "If Charles Spurgeon, John Owen, and [solemn hush here] Jonathan Edwards said it, that proves it's true!" I just picked those names out of a hat. If you're offended by my hint that those "divines" may make mistakes, you are making my point.
This is Theology By Guru. That's what the scribes did in Jesus' day. They quoted learned Rabbis and used that as their "text".
We shouldn't ignore teachers from past (or present for that matter), but they are not the authority. They may have valuable insights, but understanding the Word of God is spiritual, and every teaching of every teacher needs to be examined according to the Scripture, preferably as we're filled with the Spirit.
God is the authority, and when we hear His words, we may actually be astonished. Matthew 7:28,29 reads,
"And so it was, when Jesus had ended these sayings, that the people were astonished at His teaching, for He taught them as one having authority, and not as the scribes."
The Guru-ization of Christianity, in America at least, has dulled the blade of that astonishment. The "pure milk of the Word" re-sharpens that blade, and we can be astonished again.
There are no "great" Christians, just gifted ones who are sometimes right.