Exactly. Biblical truth is in its spiritual message, not in the hard-facts. Thus, if we assume that everything is exactly the way the Scripture says, then we must assume that either (a) God did not say mustard seed is the smallest seed and mustard tree is the tallest tree (because it is neither), or that (b) God didn't tell the truth. Yet, when taken in its proper spiritual context of the message being conveyed it really doesn't matter if botanically the statement "fits."
Let me just say this: faith is not only an encounter with God, but our relationship to God, our interaction with God on His terms. It is not a history lesson. What matters is how Christ-(un)like we are no matter how much we quote the Scripture.
Love is not something we can see, yet we know it exists; it is real. How doe we know it's real? Trough its manifestations. Love manifests itself in acts of mercy, gifts, sacrifice, etc. It is always indirect, it is always an expression of an invisible but very present and real, true and unchaining entity we know as love. It had nothing whatsoever to do with science, history or genetics.
We know God as real presence in our lives through His blessings, and through the message, the "essence" of Scripture. We must never use Scirpture to explain the world, or to deny it.
No, you cannot say that and leave it at that, this is where both Agrarian and I hit the ceiling. Biblical truth is whatever the Tradition teaches. If it teaches a hard fact then the truth is in the hard fact. "And I will give to thee the keys of the kingdom of heaven. And whatsoever thou shalt bind upon earth, it shall be bound also in heaven: and whatsoever thou shalt loose upon earth, it shall be loosed also in heaven" (Matthew 16:19). This means that if the Church says that 2 x 2 = 5 then Christ will make it 5, hard truth.