"Wherefore of these men which have companied with us all the time that the Lord Jesus went in and out among us, Beginning from the baptism of John, unto that same day that he was taken up from us, must one be ordained to be a witness with us of his resurrection" (Acts 1:21-22).

In God's program of using men to be witnesses for Him of His provision of salvation through His Son, He first chose a small group of men who were intimately associated with the words and works of Jesus Christ.  Most of them were companions of the Lord during the years of His ministry, and it was a requirement that they all be eyewitnesses of the resurrected Lord.  The Bible word for these men is Apostles.

It was these men who first carried the good news of salvation from sin to the needy world.  The Bible makes it clear that the true church is built upon the foundation they laid.  The Apostle Paul said, "According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon" (I Corinthians 3:10).

They not only did the first work of preaching the Gospel of Jesus Christ and gathering disciples into local churches, but they also left for us a written record of God's blueprint for His church.  God never intended that His work be like the "Free Expression" department of the local art show, but that it would follow the patterns He revealed to His chosen witnesses, the Apostles.
There are ramifications to these truths.  The Apostles were unique and there are none today.  Today, in 2011, we are past the foundation stage of the church and the eyewitnesses of Christ's resurrection are no longer with us.  Secondly, the teachings of the, preserved in the Holy Scriptures, continue to be God's authoritative message of real Christianity.  Every worldview, religion, or ism in the world rests upon certain precepts accepted by faith.  Even atheism has its dogma and its prophets who must be accepted on the basis of some kind of authority claimed.
Those who are Bible-believing Christians need not be bashful about living by the well-authenticated,  body of truth of Christianity, the testimony of God's Apostles preserved for us in the Holy Bible.
"And one of them, named Caiaphas, being the high priest that same year, said unto them, Ye know nothing at all, Nor consider that it is expedient for us, that one man should die for the people, and that the whole nation perish not. And this spake he not of himself: but being high priest that year, he prophesied that Jesus should die for that nation; And not for that nation only, but that also he should gather together in one the children of God that were scattered abroad" (John 11:49-52).

Caiaphas intended his words in a very different sense than the true testimony they gave of the saving work of God through Jesus Christ.  He meant to justify the murder of an innocent man as a political expediency.  Yet it was God's purpose that the High Priest's office should be one of His witnesses, and so it came to pass, even without the willing cooperation of Caiaphas.  His words said more than he knew.

At a later occasion, when the crowds loudly heralded Jesus' entry into Jerusalem as their king, the Pharisees protested that testimony.  But Jesus answered them, "I tell you that, if these should hold their peace, the stones would immediately cry out" (Luke 19:40b).  Nothing could stop the witness program of God with respect to His Only Begotten Son, Jesus Christ.  And God has made His witnesses powerful and compelling in the precincts of our individual hearts by the confirming ministry of His Holy Spirit.
Each of our hearts is like a little judgment bar that must consider the evidence and pass a verdict.  However, the judgment will not determine His sentence, but our own.  If we reject God's compelling testimony concerning His Son for any of the countless reasons that spring up in the sinful heart of man, we cut ourselves off from the only way of salvation from sin - in this world or the next.
It is difficult for human hearts to accept the testimony of God's Word, for in doing so we condemn ourselves.  But in God's grace, those who do acknowledge their sin are the ones that receive his forgiveness.  The Bible witnesses both of our fallen sinful condition and of God's loving Saviour who died for our sins.  Those who honestly receive that testimony by faith become God's dear children.