This is pure conjecture. First, what is the low level "true" faith?
It is the faith one has when he accepts Christ as Lord and Savior. From there, his faith will grow, although he may temporary backslide for a time here and there. The point is that God will cause the faith of the elect to get stronger as we go through our lives.
Then, how do you know that sanctification begins?
Because sanctification only applies to believers:
John 17:17-20 : [Jesus prayed:] ... 17 Sanctify them by the truth; your word is truth. 18 As you sent me into the world, I have sent them into the world. 19 For them I sanctify myself, that they too may be truly sanctified. 20 "My prayer is not for them alone. I pray also for those who will believe in me through their message, ...
Jesus was only praying for believers. There is no reason not to think that sanctification begins immediately upon belief.
Because you are tested?
Has nothing to do with it.
Or is this sanctification now a function of some other factors you didn't come up with earlier?
No other factors, just belief.
Second, how does it benefit us if finding "true" faith is salvific? Is there a greater benefit than what Christ accomplished on the Cross? Sure seems that way from the way you write.
Apostolics generally think that salvation/theosis is only possible at the very end of physical life, or afterward, so it is natural that you assume there is nothing for the believer after he is saved, except Heaven itself. In reality that is not true. The same time you spend trying to gain theosis we spend being sanctified. We grow in faith and are better able to serve Him. Our lives are better in the same way you would say your life is better as you conform yourself to Christ for theosis. We don't do it in order to gain salvation, we do it as a result of it.
Third, our sanctification make us more "useful" [sic] to God so He can finish His "plan?" Are we "helping" God along?
No, we are being used as His tools to accomplish His plan. In His love and mercy, He lets us experience that as participation. We are benefited the same way a four-year-old girl is benefited from thinking she is "helping" her mommy bake a cake. She is very happy to be a part of it.
This brings up some problems, FK. What about Judas. Was he also "helping" God accomplish His "plan?" Was he also "sanctified?"
Judas was used, but he was never sanctified because he was never a true believer.
Does this mean that somehow, in a twisted heretic way, Judas was really a "friend" of Jesus? "Helping" Him accomplish His task?
No.
After all, without Judas' betrayal, Jesus could not die for our sins!
Judas did not cooperate, he only followed his sin nature. No thanks goes to him. If anything it would be your side that would be thanking Judas because he used his free will and that resulted in Jesus saving us from our sins. Judas acted freely and that facilitated Jesus dying.
AMEN. We are beneficiaries of Christ's life insurance policy. He dies. We gain. And that life insurance policy was not taken out by us, but by God on our behalf from before the foundation of the world.
If anything it would be your side that would be thanking Judas because he used his free will and that resulted in Jesus saving us from our sins.
If I might add, Judas would be using his "gift" of free will, as the RCC and EO constantly tell us.
With "gifts" like that, who needs coals of fire on his head?