Each of us must have a personal relationship with God the Father and Jesus Christ in order to please God and to be saved.
In our relationship with God, we must desire to do God's will. Part of doing God's will includes supporting God's work of preaching the gospel to the world and feeding the flock with spiritual instruction. To do this effectively we should want to support an organized fellowship that is doing that effectively.
We should also have the humility to realize we ourselves need to be fed by God's ministry, and we should seek out a fellowship that will give us good instruction according to God's word.
Usually if we are studying and believing the Bible, we will be able to discern if a minister's preaching to us is speaking according to the Bible or not. We can learn to tell if we are hearing the voice of Christ speaking through the minister or the voice of a stranger. "I am the good shepherd; and I know My sheep, and am known by My own. As the Father knows Me, even so I know the Father; and I lay down My life for the sheep. And other sheep I have which are not of this fold; them also I must bring, and they will hear My voice; and there will be one flock and one shepherd" (John 10:14-16). "My sheep hear My voice, and I know them, and they follow Me" (John 10:27). "Yet they will by no means follow a stranger, but will flee from him, for they do not know the voice of strangers" (John 10:5). Christ says that members of His Church will leave a fellowship if they hear the voice of a stranger more than His voice.
Choosing the right organized Church of God to support and attend can be extremely important.
Yet, membership in a Church of God fellowship, no matter how righteous the leadership, ministry, and membership might be, will not by itself save us. God will judge us based on the fruits we produce individually. He will judge us according to our faith, obedience, and works, not that of the leaders and members of the fellowship we attend.
Notice this passage: "The word of the Lord came again to me, saying: 'Son of man, when a land sins against Me by persistent unfaithfulness, I will stretch out My hand against it; I will cut off its supply of bread, send famine on it, and cut off man and beast from it. Even if these three men, Noah, Daniel, and Job, were in it, they would deliver only themselves by their righteousness,' says the Lord God. 'If I cause wild beasts to pass through the land, and they empty it, and make it so desolate that no man may pass through because of the beasts, even though these three men were in it, as I live,' says the Lord God, 'they would deliver neither sons nor daughters; only they would be delivered, and the land would be desolate" (Ezekiel 14:12-16).
The specific context of this is national punishment that comes upon a land for its sins. But there is a principle involved that can apply to the Church of God because this shows how God thinks. We are judged individually. We will not escape a punishment because of our leaders in the Church. We cannot ride other peoples' coattails into the kingdom of God or the place of safety.
So if the top leaders and your pastor in the fellowship you attend are the most righteous men on the face of the earth, that does not guarantee you a seat in God's kingdom or the place of safety during the tribulation. You must believe and obey God personally or you will not make it. Being in the right organization isn't enough if you are not seeking a close personal relationship with God.
Your first responsibility is to draw close to God in Bible study, faith, obedience, prayer, fasting, and meditating about God's plan, His law, His way of life. Then, let God lead you to the fellowship He wants you to support.
Putting an organization first is the wrong priority.
Put God first, and you will have the right priority. Then God will lead you to know what organization you should attend and support, and He can empower you and equip you to serve Him most effectively in that organization.