1 Now in these days when the disciples were increasing in number, a complaint by the Hellenists (Greek-speaking Jews) arose against the Hebrews because their widows were being neglected in the daily distribution. 2-3 And the twelve summoned the full number of the disciples and said, “It is not right that we should give up preaching the word of God to serve tables. Therefore, brothers, pick out from among you seven men of good repute, full of the Spirit and of wisdom, whom we will appoint to this duty. 4 But we will devote ourselves to prayer and to the ministry of the word.”

5-6 And what they said pleased the whole gathering, and they chose Stephen, a man full of faith and of the Holy Spirit, and Philip, and Prochorus, and Nicanor, and Timon, and Parmenas, and Nicolaus, a proselyte of Antioch. These they set before the apostles, and they prayed and laid their hands on them. 7 And the word of God continued to increase, and the number of the disciples multiplied greatly in Jerusalem, and a great many of the priests became obedient to the faith. Acts 6:1-7 English Standard Version

What's the important truth about Christians we learn from vs 1?

When people believe the message of salvation through faith in Jesus Christ, it doesn't mean they become faultless. This is very true of new believers, but true also of those who've been Christians for many years. Things that others do can still niggle us, and there can be fall outs. This is why the apostles wrote so much in their letters about how Christians should strive to live in ways that are consistent with the new life they have received.

We see how the apostles responded to the unhappy situation which had arisen in Jerusalem, and how it met with the approval of all the new Christians. The result was that the word of God continued to increase, and many more people, including Jewish priests, became Christians. But is there a conflict about what Jesus had taught His disciples concerning humility, when He washed their feet like a lowly servant, and the apostles not wanting to 'serve tables'?

Not at all. As in all things in life, there will always be priorities. It was important that they should be freed up to take God's message into the world as Jesus had called them to do. Even that task would need to be done in the humility Jesus had given them an example of. But what we do see here is an important lesson for the day when there would no longer be apostles. What pattern did they set out for appointing people to spiritual tasks? (vs 2-3)

The believers themselves were to choose men whose lives gave evidence of spiritual maturity and godliness. And this was just for the more menial task of overlooking the distribution of help to the needy. Later on in the New Testament there are sections which deal with appointing elders and deacons in congregations, and there is little difference in the 'qualifications' looked for. For example, when Paul spoke of appointing overseers in a Church, he then said: “In the same way, deacons are to be worthy of respect, sincere, not indulging in much wine, and not pursuing dishonest gain. They must keep hold of the deep truths of the faith with a clear conscience. They must first be tested; and then if there is nothing against them, let them serve as deacons.” (1 Timothy 3:8-10)

It seems that in the days of the apostles they, and those acting on their behalf like Timothy, had a big part in choosing the overseers. I gather that some denominations have held to a system that teaches that this role continued through the ages, and it is up to the hierarchy of a denomination to appoint the overseers. Other congregations have chosen, wisely I believe, to follow the pattern in today's verses. Namely, that we are to “pick out from among ourselves men of good repute, full of the Spirit and of wisdom” and appoint them to the various ministries of the Church.

Neither the apostles, nor the seven men set apart that day, were given special distinguishing garments to wear! What set them apart was that they were men of good repute, full of the Spirit and of wisdom. And, through God's blessing, the gospel continued to increase, and the number of the disciples multiplied greatly. God’s work carried out in His way, is always the best path to follow.