There is a discussion going on over at www.dougwils.com about signs and seals. One fellow is saying that signs are like sign posts along the way that signify that a city is coming up and if you stay on this road you will soon be at the place you want to be. But he is careful to make sure we understand that the sign is not the thing signified. The sign is not the city. In this illustration this is obviously true.
The other fellow is saying that the sign is like a wedding ring. When you see the sign you know that the wearer is married. But in this case the sign is the thing that makes the thing signified the thing itself. A man is not married if he doesn’t have the wedding ring. This is particularly true when you add the idea of a seal to the mix.
In the first fellow’s case, the seal doesn’t seem to have any meaning apart from its proximity to the word sign. Throughout his whole discussion (you can find it here) he never discusses what a seal is.
A seal, however, is the thing that makes an event a fact. The seal makes an act official. For example, when a letter is written by a king it is not an official letter until he puts his seal to it. The king melts a bit of wax and drips it into a blob on his paper and then presses the official seal into the wax and thus the letter becomes official. In the same way, a wedding is official when the seal of the wedding is put on the finger. Thus the ring is both a sign and a seal of the wedding.
The Westminster Confession of faith (XXVIII, 1) says this about baptism “Baptism is a sacrament of the new testament, ordained by Jesus Christ, not only for the solemn admission of the party baptized into the visible church; but also, to be unto him a sign and seal of the covenant of grace, of his ingrafting into Christ, of regeneration, of remission of sins, and of his giving up unto God, through Jesus Christ, to walk in newness of life.” Notice that it uses the words sign and seal. It says that baptism is a sign and seal of the covenant of grace, of ingrafting into Christ, of regeneration, or remission of sins…. The question, then, is which way is the confession using the terms sign and seal?
I can see how a person might take the word sign in either of the ways stated above. A fellow could say that they Westminster folks meant that baptism is a sign pointing to the covenant of grace, ingrafting into Christ, regeneration, remissions of sins, etc. But in what other way could you take the seal part of the words? How can you take seal in any other way than to say that baptism seals you into the covenant of grace, etc.? When you are baptized you are officially in the church of Christ? The stamp is on you. You have been put into Christ.
The most natural way to take this is to say that baptism is like the official seal of the King going into the soft wax. It is a seal of our entrance into the covenant of grace, but it is also the sign of that entrance into the covenant of grace. A sign like the wedding ring, not like the sign post.