In Titus 3, we read: 

But when the goodness and loving kindness of God our Savior appeared, he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit, whom he poured out on us richly through Jesus Christ our Savior, so that being justified by his grace we might become heirs according to the hope of eternal life. (vv. 4–7) 

This passage seems to be something of a theological synopsis for Paul, since he follows with: “The saying is trustworthy, and I want you to insist on these things” (v. 8). Here again justification is set in light of becoming an heir of eternal life. This inheritance is presumably apocalyptic, associated with “the appearing of the glory of our great God and Savior Jesus Christ” (2:13). The Parousia thus is the defining event within which Paul theologizes about the first appearance of the Messiah, “our Savior” (vv. 4, 6). In this way, we are saved from the wrath and judgment associated with the Parousia by means of the cross. Paul’s understanding of the death of the Messiah as the agency of divine justification and acquittal fits well within a Jewish apocalyptic view of the Parousia. The claim often made that Paul was realizing or redefining his eschatological expectations in his use of “justification” seems unfounded.   

...Paul understood the death of the Messiah as the sacrificial means by which Israel’s God had chosen to reconcile humanity to himself, and this death was understood primarily in context to Jewish eschatology. Divine wrath, judgment, and recompense are coming on the last day. The death of the Messiah propitiates this wrath, justifies the guilty, and pays their debt. In this way, Paul’s presupposed Jewish apocalyptic worldview remains fundamentally unchanged as he theologizes about the crucifixion of God’s Messiah. -John P. Harrigan