Ephesians 2:9

it is not from works, so that no one can boast.

This is a very short verse, but it is packed with insights.

We should not think that we are saved by a mixture of faith and works, even if we call them good works. It's like electricity. There is the source, and there is the effect.

No one confuses the effect with the cause.

But sometimes, when it comes to salvation, we want to confuse cause and effect. Paul does not want that. He does not want you to think there is something inherent in you that led to salvation, as if you are some sort of superrace and inherently special. And he said in the last verse that by grace you are saved through faith, and it is not from yourselves, but it is the gift of God. That means it is something from outside of you acting on you. 

That is why, before telling you that by grace you were saved, Paul ensured that you know that there was nothing special about you to make you saved. You and I were like everyone else, dead in offenses and sins (Ephesians 2:1). We should not lose that vision. If not, we might begin to look down our noses at the unsaved, feeling superior to them, which is why Paul screamed through the pages of Ephesians: "By grace you are saved!" 

And there is the matter of boasting mentioned in this verse.

God ensured that things happened the way they did so that no one could boast. And the boasting can be to other people.

Paul knew this well when he said he had many things to boast in, including being an Israelite, a Pharisee, and an outstanding one at that (Philippians 3:4–6).

When Paul said it is not by works, he was also saying there is no ladder to reach salvation. It might seem like a process in the sight of men. But there is no progress to be made in wearing your boots and clothes while saying you are walking to the moon.

There is no process to becoming saved. Nothing guarantees salvation, is what I am saying. It's a gift of God. Someone might say," No, it's the grace that is the gift of God, not the faith; you must have faith by yourself.

There is some truth in that, but it does not take us all the way there. It's like saying, "it's the house that is a gift; you still have to use the key to open it to live in it." There is some truth to that, but if the house (salvation by grace alone) is a gift, the key (faith) to open it has to, by necessity, be a gift. And the fact that you have the key means you (individually) were in the mind of the one gifting the house. Therefore, God ordained you to be saved before the foundation of the world (Ephesians 1:4).

And you either have the faith, or you don't. Either God gave it to you, or He didn't. We are all dependent on the mercy of God, on the wealth of His grace, which I define as His love in transformative action.

If it is by works, then we can say God owes us. But God owes no man anything, since everything comes from Him; He is the grounding of existence, the grounding of reality, the essence of essences. 

And, proceeding with the house analogy, if it is by works, we need to keep up with the mortgage; otherwise, it can be taken from us, and everything would be lost. Therefore, you cannot maintain your salvation; your salvation actually maintains you.

To recap, there are two places Paul wanted to make clear that faith for salvation does not come from.

Another point that lines up with those thoughts is that it is not inherited; it is not genetically transmitted. There is no predisposition to the saved from genetics. It is not from yourselves. There are no superior races when it comes to salvation. 

All means all, and freely means freely. 

But what about the unsaved? We can conclude that God's act of saving was a demonstration of His mercy, and God's inaction of saving was a demonstration of His wrath.

It's just as God had to actively protect Job's house for it to be protected, but does not have to actively harm him for him to be harmed; He only had to not protect him.

That's a nuanced theological view, but the point is not to continue wondering about the unsaved as if God is unjust. When Peter asked Jesus about John, Jesus told him, “What concern is that of yours? You follow Me!” (John 21:22). 

The psalmist says,

That's a point of view. But sometimes there is the fun and excitement to know the deep things of God (1 Corinthians 2:10). But when that leads to distrust in God, as with Eve, we have a problem; the serpent is now involved in the inquiry. That is the truth.