The following is an excerpt from The MacArthur New Testament Commentary on Ephesians 2.

For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, that no one should boast. (2:8–9)Our response in salvation is faith, but even that is not of ourselves [but is] the gift of God. Faith is nothing that we do in our own power or by our own resources. In the first place we do not have adequate power or resources. More than that, God would not want us to rely on them even if we had them. Otherwise salvation would be in part by our own works, and we would have some ground to boast in ourselves. Paul intends to emphasize that even faith is not from us apart from God’s giving it.

Some have objected to this interpretation, saying that faith (pistis) is feminine, while that (touto) is neuter. That poses no problem, however, as long as it is understood that that does not refer precisely to the noun faith but to the act of believing. Further, this interpretation makes the best sense of the text, since if that refers to by grace you have been saved through faith (that is, to the whole statement), the adding of and that not of yourselves, it is the gift of God would be redundant, because grace is defined as an unearned act of God. If salvation is of grace, it has to be an undeserved gift of God. Faith is presented as a gift from God in 2 Peter 1:1, Philippians 1:29, and Acts 3:16.

The story is told of a man who came eagerly but very late to a revival meeting and found the workmen tearing down the tent in which the meetings had been held. Frantic at missing the evangelist, he decided to ask one of the workers what he could do to be saved. The workman, who was a Christian, replied, “You can’t do anything. It’s too late.” Horrified, the man said, “What do you mean? How can it be too late?” “The work has already been accomplished,” he was told. “There is nothing you need to do but believe it.”

Every person lives by faith. When we open a can of food or drink a glass of water we trust that it is not contaminated. When we go across a bridge we trust it to support us. When we put our money in the bank we trust it will be safe. Life is a constant series of acts of faith. No human being, no matter how skeptical and self–reliant, could live a day without exercising faith.

Church membership, baptism, confirmation, giving to charity, and being a good neighbor have no power to bring salvation. Nor does taking Communion, keeping the Ten Commandments, or living by the Sermon on the Mount. The only thing a person can do that will have any part in salvation is to exercise faith in what Jesus Christ has done for him.

When we accept the finished work of Christ on our behalf, we act by the faith supplied by God’s grace. That is the supreme act of human faith, the act which, though it is ours, is primarily God’s—His gift to us out of His grace. When a person chokes or drowns and stops breathing, there is nothing he can do. If he ever breathes again it will be because someone else starts him breathing. A person who is spiritually dead cannot even make a decision of faith unless God first breathes into him the breath of spiritual life. Faith is simply breathing the breath that God’s grace supplies. Yet, the paradox is that we must exercise it and bear the responsibility if we do not (cf. John 5:40).

Obviously, if it is true that salvation is all by God’s grace, it is therefore not as a result of works. Human effort has nothing to do with it (cf. Rom. 3:20; Gal. 2:16). And thus, no one should boast, as if he had any part. All boasting is eliminated in salvation (cf. Rom. 3:27; 4:5; 1 Cor. 1:31). Nevertheless, good works have an important place, as Paul is quick to affirm.