Justification is not the entirety of salvation, but it is an essential component of it.
What is justification? The declaration that a person is innocent in the sight of God.
Who/what justifies? God the Father.
Why does he justify? His grace. (Note: “Grace” in the Bible may mean either the giver’s generous disposition or the gift itself. The former is meant here.)
How can he justify? The death, resurrection, and ascension of his Son, Jesus Christ, on people’s behalf and in their place.
Whom does he justify? People who place their sole hope for justification in Jesus (also known as “faith”) and profess it.
What is the evidence of justification? The believer’s obedience to the will of God.
Who/what produces that evidence? The Holy Spirit of God living in the believer.
This is the classic Protestant teaching on justification. The Protestant view and mine is that addition, subtraction, or modification of the substance (not mere wording) of these answers is not only an error but probably a fatal one.