I do agree on this point (not the overall position though). Faith is something that should be exercised. The question however is, what is the cause of this exercising of faith? God (and his grace) is the cause of this faith.
Phil. 2:13 — for it is God who works in you, both to will and to work for his good pleasure.
Look at the context:
Php 2:12 Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling.
Php 2:13 For it is God which worketh in you both to will and to do of his good pleasure.
Php 2:14 Do all things without murmurings and disputings:
--It is quite evident that Paul is not talking about salvation here but the Christian walk. We have no dispute here.
However, God does not give faith (the fruit of the Spirit, and a spiritual gift) to the unregenerate. No one on this board has been able to demonstrate that yet.
Heb. 12:2 — Jesus, the author and finisher of faith
OUR faith, our salvation, the believer's faith, but not to the unregenerate.
Acts 18:27 — And when he was disposed to pass into Achaia, the brothers wrote, exhorting the disciples to receive him: who, when he was come, helped them much which had believed through grace
The ESV says:
Act 18:27 And when he wished to cross to Achaia, the brothers encouraged him and wrote to the disciples to welcome him. When he arrived, he greatly helped those who through grace had believed,
--Paul was returning back to Antioch. On the way back he was confirming the believers in the churches which he had already established. These were believers who had already come to Christ in faith. We all come by grace through faith (Eph.2:8,9).