Is there a lacuna in baptismal theology?

First, a long quote from Colin Gunton about baptism, that sums things up pretty well.

The practice of baptism, as it has taken place in recent years, therefore raises the question of ‘validity’.  Here I want to make two points.  The first is to repeat that the basis of the rite, and so of its validity, is the death of Jesus on the cross.  There is nothing automatically valid about the saying of particular words over, and the application of, water, in whatever way, to a person.  But, second, given that the words have been said and that water used in a public ceremony, we deny the reality of that baptism at our peril, because by doing so we risk unbelief in the promise of God which underlies the use of the words.  If the baptism was performed in the light of the promise, then we are bound to say that those who are baptized have been brought into relation to Christ.  What right have we to deny it?  We may like neither the pastoral practice of indiscriminate baptism nor the fact that many baptisms are performed out of the context of the regular worship of the local community.  But that does not license us to decide that the baptism was not a ‘real’ baptism.  Baptism is a churchly and public rite before it is an individual or experiential one…We must confess that so many baptisms have not, in practice, expressed the churchly dimension adequately.  But is that enough to deny that they were baptisms? (Father, Son and Holy Spirit, p.209). 

Does Gunton capitulate to the logic he’s trying to avoid here? He says that baptism is about entry to the community of God’s people, but then when he’s talking about baptism of, say, an infant who comes from an unbelieving family and is also unbelieving, he switches to the language of God’s promise and emphasising the ‘objective’ side of baptism. But can a rite without any integration into a community actually integrate you into a community? Surely not, and Gunton is right to stress baptism is primarily about being brought into relation with God through relation with his people. Yet if baptism is not an automatic ‘get out of hell free’ card as it seemed to be for the earlier tradition, then why begin to talk about it as ‘effective’ or ‘real’ precisely in those cases when it is completely cut off from any integration with a community.

             We’d like to think that god does something to someone in baptism beyond simply them joining a community.  If joining the church was all that mattered, we wouldn’t need to baptise, we could have any joining ceremony we liked, or none.  It is not just that the symbolism is particularly fitting, it is that we think God does something to a person, though they may not experience it or remember it.  But that is a claim that cannot easily, if at all, be verified or falsified.  And what is this ‘thing’ God does to someone?  If a baby is baptised but s/he and her/his family are never part of the church, what difference can we say it makes to her/his life?  How could we possibly know?  (All of this, incidentally, is why rigorous catechetical practices are so good: baptism consummates your membership of the community as the culmination of learning to be a part of it through the catechism.  The Catholics and Orthodox have it right here).