That's true about increasing one's faith. It must come from God. What was not addressed was where the "faith seed" comes from in the first place.
The "faith seed" comes from God. We are "unprofitable servants" because what we have is given to us by God-we don't generate faith on our own.
The seed of faith does indeed come from God, but the paradox that you see between mature faith and free will disappears if you consider the scripture I showed you, describing the growth of the embryonic faith through the good works of free will.
Eh, this part is wrong. The gospel does not say so. It says, the servant is unprofitable because he did not go beyond the obligation, --- his work lacked charity.