Is Baptism a ticket?

To this question, Walther says this - from Thesis XXI of his book God's No and God's Yes.

Rom 3:28: If I am justified, if I obtain grace by my act of submitting to baptizing or by my act of going to Communion, I am justified by works, and at that altogether paltry works, scarcely worth mentioning. For that is what Baptism and Holy Communion are when viewed as works that we perform. It is a horrible doctrine, wholly contradicting the Bible, that divine grace is obtained if a person at least makes external use of the sacraments. The truth is that Baptism and Holy Communion place any person under condemnation who does not approach them with faith in his heart. They are means of grace only for the reason that a divine promise has been attached to an external symbol. Having water poured on me is of no benefit to me. Nor am I benefited by actually receiving the body and blood of the Lord. It is of paramount importance that I BELIEVE, that I regard, not the water in Baptism, but the promise which Christ has attached to the water. It is this promise that requires the water; for only to it has the promise been attached

(the emphasis is mine).