Maybe my understanding is wrong, but the way I've interpeted 6:1 is to mean that formerly the Jews were supplying the needs of the widows since they had nobody to supply them with food. Once they became Christians, the Jews no longer took care of them and Christians took over the load. So the apostles appointed people especially to serve them since they were a little overworked themselves.
Is the purpose of a deacon to serve food to widows in a Jewish temple?
Forgive me if this has been answered already. You go to the dentist and you miss a couple hundred posts these days. The word deacon from the Greek diakonos which means to minister or to assist. Caring for the widows was a clearly a major concern in the early days of the Church so it stands to reason that one of the duties of the deacons would be to do just that. The lay office of deaconess was instituted very early on in order to minister to the needs of the women that modesty prohibited men from serving.
Please pardon my grammar on that last sentence. Hope you get where I drifted to.