I do not, however, find in the New Testament or in the earliest Christian fathers any suggestion that those at present in heaven or (if you prefer) paradise are actively engaged in praying for those of us in present life. Nor do I find any suggestion that Christians who are still alive should pray to the saints to intercede to the Father on their behalf. [… If] part of the work of the ascended Christ is indeed to be ruling the world as the agent of his Father, we might indeed suppose that the dead are somehow involved in that[. … But] I see no evidence in the early Christian writings to suggest that the Christian dead are in fact engaged in work of that sort, still less any suggestion that presently alive Christians should, so to speak, encourage them to do it by invoking them specifically.
(N. T. Wright, Surprised by Hope, pp. 172-3)
I see no evidence in early Christian writings to suggest all sorts of things that we have fairly good evidence for – that the Earth orbits around the Sun, that one can generate electricity from running water, and so on.
More specifically, Wright’s response is a good way to not figure something out. Intercessory prayer through saints is an empirically investigable phenomenon. Instead of saying “I don’t find evidence that supports this idea in early Christian writings” and then stop there, it is better to ask: what is the evidence that intercessory prayer through saints works?
People pray to the saints for help in specific things. One example in Catholicism is St. Anthony, and one thing he is commonly asked for help on is finding lost things. So, does this practice work?
There are many Catholics who attest to it working, and many anecdotes that seem hard to explain conventionally. A pattern is: they try to find something for an extended period of time, then they pray to St. Anthony for help in finding it, then not long after they find it through an unlikely coincidence.
If there is evidence, then you have to develop a theory to explain it. Wright doesn’t even get to this point, because he’s so blinkered by what is or isn’t in early Christian scripture. Early Christian scripture is not a guide to every empirical matter, or (in specific) every practice relevant to Christians.
Saints are prayed to for help because it seems to work, and some people seem to find this practice more tangible or practical than praying directly to God, say.
Yet, in a more general sense, it seems odd to say one shouldn’t ask another human (whether they are in the presence of God, i.e., a saint, or not) for help on something. If I ask someone to help me in building a house, we don’t say that’s idolatrous or semi-paganism, or some such thing. We recognize these are human beings, not God. We further recognize that certain things in the universe have certain influence and are appropriate to talk to or work with (whether it’s another human, a draft horse, a lever, and so on) when it comes to certain tasks. This is compatible with and if done properly complementary to developing an ongoing relationship with God – God works through things, according to Christianity. Just as human beings here and now have certain abilities, it seems saints in the presence of God would also have certain abilities (as Wright himself seems to think in a nearby section of the book).
So, Wright’s underlying concern about what praying to saints entails is wrong-headed, and his specific treatment of the issue is, however correct in terms of early Christian scripture (and regardless of how relevant that method is when trying to figure out what early Christians did and believed), beside the point. We are not living in A.D. 70.