Deacons in the Local Church
In God’s wisdom, He authorized elders to rule over His local church, He authorized preachers and teachers help spread the Word, and He authorized deacons to be servants.  The word “deacon” means servant, waiter.

The characteristics or qualifications of a deacon are listed in 1 Timothy 3:8-13,
“8 Likewise deacons must be reverent, not double-tongued, not given to much wine, not greedy for money, 9 holding the mystery of the faith with a pure conscience. 10 But let these also first be tested; then let them serve as deacons, being found blameless. 11 Likewise, their wives must be reverent, not slanderers, temperate, faithful in all things. 12 Let deacons be the husbands of one wife, ruling their children and their own houses well. 13 For those who have served well as deacons obtain for themselves a good standing and great boldness in the faith which is in Christ Jesus.”

Deacons hold an office or position, “...let them serve as deacons...”  This is a special position in the church with special qualifications and with special responsibilities, that being a servant to the local congregation.
Since the role of deacons in the church is that of a servant, they would naturally be charged with doing things to relieve the temporal affairs and burdens from the elders and preachers.  Their duties are not specifically listed in the Bible, so their duties are left primarily up to the elders.  Their duties generally include, but not limited to, taking care of the members needs and taking care of the meeting place.  Often, deacons arrange the assignments for services to insure an orderly worship service.

For example, the early church at Jerusalem had many things taking up the time of the apostles.  One such matter was relieving the needs of the widows as found in Acts 6:1-6,

“1 Now in those days, when the number of the disciples was multiplying, there arose a complaint against the Hebrews by the Hellenists, because their widows were neglected in the daily distribution. 2 Then the twelve summoned the multitude of the disciples and said, “It is not desirable that we should leave the word of God and serve tables. 3 Therefore, brethren, seek out from among you seven men of good reputation, full of the Holy Spirit and wisdom, whom we may appoint over this business; 4 but we will give ourselves continually to prayer and to the ministry of the word.”
5 And the saying pleased the whole multitude. And they chose Stephen, a man full of faith and the Holy Spirit, and Philip, Prochorus, Nicanor, Timon, Parmenas, and Nicolas, a proselyte from Antioch, 6 whom they set before the apostles; and when they had prayed, they laid hands on them.”

The widows were being neglected in the daily ministration (verse 1).  The apostles were busy preaching and teaching the Word of God to the extent that they needed to stop “serving tables.”  So, seven men were selected by the disciples and presented to the apostles for approval.  The disciples were given criteria to use, “men of honest report, full of the Holy Ghost and wisdom.” (verse 3) 

These men were not called “deacons” but, clearly, they were servants of the church.  It is noteworthy that two of these men, Stephen and Phillip, later became evangelists.

While this is one example of the use of deacons, a necessary inference dictates that they are charged to relieve the elders and preachers in matters that would distract them from discharging the responsibility of caring for the spiritual needs of its members.