DHK, I ask this in all sincerity.
How can faith be innate and a fruit of the Spirit? I have a hard time reconciling these two trains of thoughts. If everybody has faith, would they not have a fruit of the Spirit?
Well, "faith is faith" as in its nature or definition. It is confidence, trust, belief, in the word of another. We all practice faith in one way or another every day, but not always spiritual faith.
If I enter into a plane and hope it takes me from some city in America to London, do I not put my faith in:
1. The word of the Airline that promised me that that's what they said they will do.
2. The ability of the pilot to get me safely there.
3. The capability of a designed invention much heavier than air or gravity to lift over a couple of hundred people high into the air and get them all the way across the ocean safely.
4. The "hope" that I will not be shot down by terrorists.
My faith is initially in the airline because that is who I paid the money to, and they are the ones that made the promise to get me where I want to go.
A good definition of faith:
Romans 4:20 He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;
21 And being
fully persuaded that, what he had promised, he was able also to perform.
--Abraham was fully persuaded that what God had promised God would perform.
In the secular world, am I fully persuaded that what the airline promised they will do?
In regards to salvation:
Is the unsaved person fully persuaded in the message of salvation that what God has promise is true? Will God perform what he said he would--save that person? (not discounting the work of the Holy Spirit). If he is fully persuaded, confident of that message, then he believes it, not just academically, but acts on it, accepting by faith Christ as Savior, just as Abraham acted on the promise given to him.
Faith in the Christian life does not change in its nature: Belief, trust, confidence, etc.
We now have a relationship with Christ. As the relationship grows so does faith, as does love, joy and the other fruits of the Spirit. They are given "without measure." As the song writer put it: "Count your blessings, name therm one by one..." They are numerous. The capacity for the believer to exercise both faith and love is intensified so much the more. And still it can grow, as the disciples demonstrated: "Lord, increase our faith."