The First Ecumenical Council
In studying the Council of Jerusalem we learn about the functioning of Church leadership.
(Acts 15:1) And certain men which came down from Judaea taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved.
This council was convoked [called] in response to false teaching by Jewish Christians.
(Acts 15:2) When therefore Paul and Barnabas had no small dissension and disputation with them, they determined that Paul and Barnabas, and certain other of them, should go up to Jerusalem unto the apostles and elders about this question.
(Acts 15:4) And when they were come to Jerusalem, they were received of the church, and of the apostles and elders, and they declared all things that God had done with them.
(Acts 15:5) But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses.
The false teachers were also present in the council. Thus, we should expect representation from all sides of a controversy at Church councils.
(Acts 15:6) And the apostles and elders came together for to consider of this matter.
Those who believe that the role of apostle ended with the death of the last apostle must also accept the notion that Church councils are no longer possible; who is qualified to decide at a council except those with an apostolic role. Thus, there could be no council of Nicaea or Nicene creed unless we accept that the bishops are apostles.
Peter defines the key ingredients to a solution. Note that he does not in the slightest attempt to appease the dissenters.
(Acts 15:7) And when there had been much disputing, Peter rose up, and said unto them, Men and brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe.
(Acts 15:8) And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as he did unto us;
(Acts 15:9) And put no difference between us and them, purifying their hearts by faith.
(Acts 15:10) Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?
(Acts 15:11) But we believe that through the grace of the Lord Jesus Christ we shall be saved, even as they.
Barnabas and Paul provide supporting evidence for Peter's assessment. Notice that at this stage of the Church, miracles are used by God to show the way of truth.
(Acts 15:12) Then all the multitude kept silence, and gave audience to Barnabas and Paul, declaring what miracles and wonders God had wrought among the Gentiles by them.
James accepts Peters analysis and supports it from scripture. He proposes a solution which everyone agrees with.
(Acts 15:13) And after they had held their peace, James answered, saying, Men and brethren, hearken unto me...
(Acts 15:14) Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name.
(Acts 15:15) And to this agree the words of the prophets; as it is written,
(Acts 15:16) After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up...
(Acts 15:17) That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things.
(Acts 15:18) Known unto God are all his works from the beginning of the world.
(Acts 15:19) Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God...
James decides how to resolve the matter and he feels he has the authority to do so. No one disputes his decision.
(Acts 15:20) But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
(Acts 15:21) For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
(Acts 15:22) Then pleased it the apostles and elders, with the whole church, to send chosen men of their own company to Antioch with Paul and Barnabas; namely, Judas surnamed Barsabas, and Silas, chief men among the brethren...
(Acts 15:23) And they wrote letters by them after this manner; The apostles and elders and brethren send greeting unto the brethren which are of the Gentiles in Antioch and Syria and Cilicia...
(Acts 15:24) Forasmuch as we have heard, that certain which went out from us have troubled you with words, subverting your souls, saying, Ye must be circumcised, and keep the law: to whom we gave no such commandment...
(Acts 15:25) It seemed good unto us, being assembled with one accord, to send chosen men unto you with our beloved Barnabas and Paul,
(Acts 15:26) Men that have hazarded their lives for the name of our Lord Jesus Christ.
(Acts 15:27) We have sent therefore Judas and Silas, who shall also tell you the same things by mouth.
(Acts 15:28) For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things;
Notice that the Holy Spirit worked through the various leaders of the councils...
(Acts 15:29) That ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well.
Three of the four decrees of this council are no longer in force. Thus, we have no reason to believe that decrees of councils are forever true. Notice thatno subsequent council reversed the decrees of the Council of Jersualem; these just sort of became irrelevant over time, through neglect. It is as if,in order for a truth to be infallible, it must be reinforced constantly from generation to generation.