One thing that I had not thought about previously is that this office has a spiritual focus. I had considered the division to be that the deacon cares for physical needs while elders care for spiritual needs. Indeed, the first deacons were called to organize the church's support of widows. But, being a deacon is far more than doling out soup at the church's soup kitchen. From our BCO, chapter 9:
It is the duty of the deacons to minister to those who are in need, to the sick, to the friendless, and to any who may be in distress.Deacons don't dole out, they minister. Note that the above quote mentions ministry to the "friendless." That ministry may certainly include physical needs, but also the love of fellow believers and the grace of the Gospel.
And, how can you minister well and correctly if you don't know right doctrine? That is a major reason we're going through the Westminster Confession and catechisms, so we know right doctrine. (We've blazed through the confession and are starting the larger catechism next week.)
One more thing on this: one of the first deacons, Stephen, is not remembered for waiting on tables, but for his doctrinally sound defense of his faith. Two lessons: 1) his ministry isn't out there for the world to see, but done quietly and without fanfare; 2) deacons must be sound and strong in doctrine and their defense of the faith.