18 Therefore, as one trespass  led to condemnation for all men, so one act of righteousness  leads to justification and life for all men. 19 For as by the one man's disobedience the many were made sinners, so by the one man's obedience the many will be made righteous. 20 Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, 21 so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.
(Romans 5:18-21 (ESV)
“So one act of righteousness leads to justification and life for all men.”
In Lutheran theology is means is and all means all, justification for all men, life for all men. This is what the act of righteousness has brought upon the world. There was and has been only one truly righteous act in the history of mankind, and it is an act of righteousness that makes others righteous, that is justifies them and gives them a “right” relationship with God. This righteous act culminates in the death of Christ, and begins its climax with the resurrection but will find completion in the judging of the living and the dead, the act itself was the Father giving his only begotten son out of love for the world that whoever believes in him would not perish but have eternal life. The Father did it out of love for the world, and so he justifies the world. All means all, just as is means is.
All are justified. All who have ever lived or will live, all who now live are justified by that act on the cross where time encountered eternity, where the infinite and eternal God was bound to time and place within the flesh of man and died for the sins of the world. This happened, it happened outside of us and therefore is true independent of anything we believe, teach or do. It is an objective fact of history as true as Caesar crossing the Rubicon, Napoleon’s defeat at Waterloo, or that fact that you were born. You can choose not to believe it, and it makes no difference it is true. Same as the fact you can choose to believe the sky is not blue, but it won’t change the fact that the sky is blue.
Justification is universal. And when it comes to justification I am a universalist. I don’t preach the gospel as if your faith makes it true. Sorry, but it just isn’t about you. Not in that way. It doesn’t depend on you. And I’m glad, because I would hate for my salvation to depend on you, actually I would really be sorry if your salvation depended on you. This is the beauty of justification. I tell you Christ died for you, he forgives your sins, and it is true. I don’t have to qualify it and ask you to believe it, then make that belief dependent upon you doing this or that, though it is sealed, strengthened and nourished by the sanctification that comes not only through the hearing of the gospel in the word, but the working of Holy Spirit in and through the sacraments of Baptism and the Lord’s Supper.
When Jesus sends us out to preach repentance and the forgiveness of sins to the ends of the world, when he sends us out to baptize all nations, he sends us out with a message that is true: Jesus died for you, Jesus rose from the dead for you. The message necessitates universality. If the message isn’t universally true, if for say it is limited to the elect, as the Calvinists say, or if it is dependent upon me believing it as those who would have you pray the sinners prayer have you believe, then I’m really not given anything to believe, and the sanctifying power of the message is undercut. The gospel sanctifies, it causes belief in that which is true. When it is limited to the elect, I have no way of knowing that I am elect. When it is made to depend on my believing it, I may as well believe I’m a millionaire. When it is made to depend on Christ, his death and resurrection, his word and promise, well then I am given something to believe, then the Holy Spirit is at work because the gospel is being proclaimed, then this justification is being applied to the subject and the subject is sanctified, brought to faith and washed clean in the waters of baptism, that the feet of his soul might be washed by Christ with his blood at the altar.