May a church assign to a servant or servants (deacons) a specific task or tasks in which they will serve the congregation and for which they will be responsible and answerable to the congregation for performing, if the church does not have elders. In other words, may they set or appoint men as servants over specified tasks (Acts 6:3) in the absence of elders?
It has been my observation that most churches do so but they avoid referring to the work as a duty of a deacon and thus avoid the issue and the need for addressing the qualifications of one who is serving the church. As an example, almost every congregation has a treasurer. He is a man serving the church in a specific task, yet without elders congregations avoid referring to the treasurer as a deacon and many men selected as treasurer would not qualify as a deacon anyway.
The case of Acts 6 is interesting because elders are not mentioned as being appointed yet. The first mention is in Acts 11:30, but by then they have already been in place and we do not know for how long.
It is sometimes argued that the deacons serve under the elders, so without elders no one can serve. But using the example of Acts 6 once again, we find that it is the church who selected the men and the apostles who appointed them to their duty (the same word used in Titus 1:5 in instructing the preacher to appoint elders). These men were not relieving the apostles of some of the apostles' duties. Rather, the apostles had asked that the men be appointed to keep the people from distracting them from their duties with their problems (Acts 6:2). Therefore, these deacons served the church and not the apostles. The apostles benefited from their service because they had less distractions, but it cannot be said that the deacons were servants of the apostles. Nor can I find an example where there is indication that the deacons served the elders.
The duties of a deacon are independent of the elders' duties. Deacons are not sub-elders or elders in training. Elders oversee, guide, and teach the members of the church. Deacons perform tasks in service to the church. If anything, deacons help the elders indirectly by handling specific tasks so that the elders are not distracted from their duties by demands of people in the church. Strangely, I'm seeing a lot of congregations treating their elders as supervising deacons. The two roles should be seen as separate jobs.
There is concern that deacons serving without elders could become rulers within a congregation, such as seen in the Baptist denomination. It is true that people over time do tend to corrupt God's plans, but the possibility of corruption does not negate the need for the duty to be done. There has always been problems with preachers running a congregation and it can be seen in the denominations "pastor" system, but it doesn't mean we cannot have preachers without elders.
Another argument is that deacons are only mentioned with elders. The case in Acts 6 demonstrates that this is not so. The use of the name "deacon" as a description of a duty is clearly used with the name "elder" as a job title. But the word "deacon" is merely the word "servant." We see service being done in Acts 6 without mention of elders. There are other cases where men are appointed to service of the church and elders are not directly mentioned, such as II Corinthians 8:18-21. To claim that deacons only exist when elders exist doesn't match what is found in the New Testament.
Ideally all congregations ought to have men serving in each of the roles of elders, deacons, and preachers. But I think it harmful to add additional rules that cannot be supported by command, example or necessary inference from the New Testament.