1.Why did the council have to meet to discuss if Jesus was the Son of God or if he was human or a spirit?
2.If God inspired man to write the Bible and he lives in me, why do I need the Bible or Jesus to tell me how to live when I can talk with him myself?
I will assume that your first question is about what is known as the Council of Nicaea, which happened in AD 325. This general council of the church was called by Emperor Constantine in order to get the church to settle a controversy which had been caused by a new teaching by the bishop Arius in Alexandria. Arius had begun to teach that Jesus was created by God. People in Alexandria had a saying that they put in the form of a song: “There was a time when he was not.” Those of us who are believers today might be surprised at the rather wide range of ideas about God which were found in the primitive church. The apostles taught that Jesus was God, that he was deity, that he was God-in-the-flesh. The apostles also taught that Jesus had human traits–that he experienced pain, and temptation and that he accepted limitations in his power while in the body. This logically raises some difficult questions. John said in John 1:1 “In the beginning was the word, and he was with God and he was God.” This statement defies some common sense human ideas. The Christian idea of Jesus is difficult to grasp. Therefore, early Christians tried to create “logical” explanations. One of them is that if Jesus was human then, like all humans, he was created. These people strongly limited the deity of Christ and emphasized his humanity. They made of Jesus a sort of sub-deity. Others, in order to explain Jesus made him less human than he was. They minimized his humanness, some even saying that he only appeared to be human. These people are known as Docetists (Greek for appear). The first group are known as Arians. A group today which can be described as Arian is the Jehovah Witness.
I have not yet answered your question. You asked why would these false theologies have been found in the church? The reason that these false theologies were in existence is that people looked for a “logical” explanation of the doctrine of God. The biblical doctrine of God, sometimes called the Trinity, is hard to grasp. How can Jesus be with God and be WITH God? Bottom line, the reason that Arianism existed back then is because humans were looking for a “logical” explanation of what the New Testament says about God. What we learn from church history is that when human beings try to use their own reasoning to create “logical” explanations of the biblical view of God, we always get in trouble. The mainline, Orthodox Christians insisted that the doctrine of God is a mystery on some level. They accepted that Jesus was who the Bible says he was, which is God-in-the-flesh, yet at the same time human. They tried to protect the mystery of God. The decision at the Council of Nicaea rejected very strongly the idea of Arianism as unbiblical. This is exactly what they needed to do.
The fact that there were groups which taught false theologies does not make the biblical statements about God any less clear. We should not be surprised that human beings had a number of teachings about God which were false. Such false theologies were bound to crop up. For us, what we can do is read the Bible for ourselves. I believe that if we let the entire Bible speak, then we will reject Docetism (Jesus was fully God but his humanity was only an appearance, but not real) and we will reject Arianism (that Jesus’ deity was not complete–that he was a created being). We should not let the fact that false teachings emerged confuse us, because the biblical picture of Jesus is clear.
For your second question, the reason that God created an inspired Scripture was so that we could have an authoritative and trustworthy source of authoritative teaching from God. In a sense, your question answers itself. You ask why we need inspired teaching if God lives in us. It is because, despite the fact that God lives in us, we need authoritative inspired teaching. Clearly, having God live in us is not enough, otherwise I suppose that God would not have given us inspired Scripture. Besides, let us assume that God does live in us as Christians. OK, but there was a time when we were not Christians, correct? Then, certainly we would not have had inspired information before we were Christians. Therefore, we would need inspired Scripture in order to know how to be saved.
But the fact is that we are humans. We are sinful. Like God tells us in Jeremiah 17:9 that “The heart is deceitful above all things, and desperately corrupt. Who can understand it”? It is an inevitable fact about human beings that they will be self-deceived. They will believe that God is speaking to them when it is really just their opinion or they are simply not even correct. Man is fallible. Mankind is sinful and we have a sinful and corrupt heart. This is still true of people who are saved in Christ. We need a source of authoritative truth. If you are talking to yourself, then how do you know what you are thinking is true? There is no way to know this. We absolutely need a source of truth. People have a lot of different opinions. Which is the correct opinion? All of us are hopelessly corrupt without God. Therefore we need a source of truth. Surely you know that you cannot trust your heart to tell you the truth. All of us follow our emotions rather than truth when the rubber meets the road. We need the Word of God to know truth. Like David said in Psalm 119: 160 “All your words are true; all your righteous words are eternal.” We can say this about the Bible, but we certainly cannot say that about our thoughts!!! No human being is a source of reliable truth, but the Bible is an inspired source of truth. Like the Bible says, “All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness.” (2 Tim 3:16) We need scripture, as it is the only source of reliable, inspired truth from God. You can talk to God, but how does God talk to you? The answer is that he speaks to you, principally, through the Bible.
I hope this helps.