Faith is a gift that we receive and is granted by the grace of God.
As for works, it is impossible to perform authentic Christian works, unless someone first has received the Holy Spirit.
To receive the Holy Spirit one must believe in Jesus Christ, fact.
Faith (to believe) comes first, then works follow from that faith.
Obviously our works are, in fact, God working in and through us.
I doubt whether anyone would seriously consider that anything in the spiritual realm. Can be directly traced to us.
Good works do bolster your faith but the first and only cause, is always Jesus Christ.
Boast in Jesus.
I totally agree it is only by grace through faith that our Christian lives are made possible, but that is not the question.
Romans 14:23 says the Christian who sins by doing what he doubts (Ro 14:5) is "condemned" not "justified".
James 2 speaks of this same issue of an ongoing need for justification by faith which is completed by works.
We know that "this is our victory, even our faith", so believers are "more than conquerors", yet Jesus says "to the one who overcomes", so, this idea of "already but not yet" pervades Christian doctrine--and justification and salvation is yet another.
"Now we are children of God, but it has not yet appeared what we shall be"
"The true light has already begun to shine, and the darkness is passing away"
I could go on and on.
We have the spirit of adoption, and yet we are not fully adopted yet--the body will be redeemed, and we will exhibit no resistance to God's will, but will have the glorious liberty of the sons of God (because we will be fully free to do as we please, because our pleasure will be God's will with no resistance in us, after we see Christ--"set your hope FULLY upon the grace to be revealed at the revelation of the Son of God").
In the Word, in prophecy, there are down payments/deposits, and then there are the grand spectacular full fulfillments.
"The way of the righteous is as the rising of the Sun, which gets brighter and brighter until the full noon day."
The Sun has risen, yet it is not yet full noon day.
So it is with justification--we are justified, and Christ has obtained many things for us, and YET it is only those who WALK in those things who will ultimately experience the full fulfillment of those things, whereas those who are "leavened" but who continue to hold on to "leaven" and not "purge it out" will not.