I could be wrong, but I understand Lutherans to think a bit more like Justification is a constantly present reality; meaning, that it is Justification by Faith Alone with every act of faith an at-that-moment-becoming reality. We must also remember that Lutherans believe salvation can be possessed absolutely; and also lost absolutely after having had it. So Luther might say, "I am Justified!" in the face of his sins and doubts many, many times; and feel that in that hour he experiences his Justification as if for the first time. He would speak this way about baptism: "I am baptized!" and take comfort in that; his old man was drowned, had just been drowned that day, and the new man risen up. Luther was a very present-hour fellow.
I believe there is something in the "present" perspective which we Reformed should also desire to affirm--because there is a "now-ness" to salvation, and it has to do with the equal emphasis we put (or should) on Spirit-wrought perseverance, as much as on any of the other parts of our salvation. Looking for resources, I recommend the Canons of Dort, ch.5. In other words, I know I am saved (and was saved in the past) because NOW I am clinging to Christ alone for salvation. Past moments are not meaningless--the "past moment" when Christ died and rose again is beyond all importance--but I do not rest in "the hour I first believed." I don't count on "evidences" of my faith. My justification, therefore, should be seen by me (in part) as having had such a powerful effect that it "feels" like it is happening every moment thereafter. "Forgetting what is behind..."
But it is probably fair to say that Reformed theology makes more use than Lutherans of the ordo salutis, the (logical) order of salvation when describing what we've obtained. And we speak often about our initial, and one-time Justification. It is a DONE deal (thanks be to God). It was "the hour I first believed," and it was never MORE sure later than at that instant. It was ENSURED with as much certainty before time, when we speak of the divine decree, election, and predestination. Which explanation then demands that we further distinguish between the decree to Justify, the Justification wrought (at the cross), and the application of Justification at the time of conversion (we are confessionally opposed to "eternal justification").
Consider this: many of us were converted as children, some so young we don't know when. But our ability to analyze and articulate a spelled out doctrine of Justification may only have happened once we were teenagers. Maybe later. But as we embraced a richer understanding of the faith we had known in simpler form, we did not then become Justified. For some, there has never been anything like an "emotional" response to the knowledge of Justification. Learning it was as "exciting" as learning noun-verb agreement, sentence diagramming, and fractions. But it is still certain-knowledge, as much as any of the other topics. But some of us have periodically meditated on the profound possession of that knowledge since we first obtained it. Sometimes we are encouraged to do so by sermons. On such occasions, we are all urged by Holy Spirit to make that doctrine a "present" reality to our mind, whether it has emotional impact or not.
I hope this is helpful.