1. Is it in the Bible?
Yes. (the word "service" is contained many times in the Bible, none of these references are of a "church service")
2. What do we believe it means?
A scheduled meeting of believers which consists largely of preordained worship and a message by the church leader.
3. What does it really mean?
The Bible makes no reference to a "church service". The term was invented by the catholic church to describe their catholic mass format. It is very clear that this same church format was and is largely adhered to by the protestant churches.
What is deceptive about this is that worship and addressing a group of believers certainly are Biblical Christian functions. A "church service" consists of Christian functions, and often the new covenant is taught--however the Biblical basis for the format of the church service is the old covenant temple, offerings, and priesthood. It is an authoritarian format. It leaves the "ministry" to be done by one or two people, and is complete preordained by these few people, which makes it disobedient to the rules for meeting as outlined in he new covenant (see 1Corinthians chapters 12-14).
It is what has been omitted from the "church service" and why, that really matters.
In the bible Christians were not lead by a repetitive schedule and preordained format. Yes there may have been worship or teaching, but they were clearly spontaneous, since the Bible makes it clear that all believers have the right to function in these activities...
26 ¶ How is it then, brethren? when ye come together, every one of you hath a psalm, hath a doctrine, hath a tongue, hath a revelation, hath an interpretation. Let all things be done unto edifying. (1Corinthians 14:26))
If "every one" has a psalm--if "every one" has a doctrine (the same Greek word meaning "teaching") it is clear that these functions are spontaneous, and therefore lead by God. All can minister. All are equals. And these rules precluded meeting in small groups as Jesus had demonstrated in His ministry. Yes, Jesus did address large groups occasionally--and so did Peter and Paul--but is there any record of them preparing their sermon?
The bigger, missing ingredient the church "service" needs is the apostleship that worship and teaching always lead to in the Bible. Look in the Bible at the group teachings that Jesus gave (as well as Peter or Paul or Stephen). It was always leading to the witnessing and release of the Gospel. the worship of the believers on the day of Pentecost lead them into he streets to witness ("the wonderful works of God" Acts 2:11)). the group teaching which followed was not addressed toward those who already believed--but toward the unsaved.
The traditional "closed off" concept of the church service has lost it's Gospel directive. If we study history, we can find where this happened and why. 1700 years ago a Roman emperor (Theodoscious by name) declared everyone in Rome a "christian" A quote from a cathoilc history book read "simple apostleship was no longer needed, new forms of ministry had to be invented."(and what was invented? --"pastoral authority"!)
It makes sense (to a dark ages mindset-!) that if everyone is a christian, and forced to attend the "church service" each week, there is no need to spread the Gospel (accept perhaps to far away lands--and so our concept of a "missionary").
Apostleship was dead. The new covenant way of operating the church was one away with, replaced by the typology of the old covenant Levitical priesthood, temple and offerings (and even though these concepts are specifically eliminated or redefined in the new testament, no one could read the Bible except for a handful of "official" church leaders).
Fast forward 1,000 years in history to the time of the protestant reformation. Yes, now the Bible is finally being published (although illiteracy is prevalent) and Biblical doctrine is returning to the church. But, the early protestant kings fully preserve the system of the church service and authoritarian church "ministry" as a affirmation of their right to be despots and a way of ruling and controlling the common people. And, the concept of a Christian nation" is still firm in he experience and largely a truth.
Why have any Gospel functioning in the church, when nearly everyone in Europe is a Christian? Look to history--even up to less than 100 years ago, churches were formed under this concept. Yes, send a "missionary" to Africa, but no need to organize witnessing within the church locally. And the church service is the name we give to the traditional agreement (convenant) Christian function in--repetitively. A function which contains an unspoken agreement that one person is the "minister"--and all the rest the non-functional "congregation".
Worship and teaching only benefit the believer.
So, what shall Christians do when they are together?
Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....Worship and teach.....
Have a church service.