The Spirit knows the mind of God and those whose eyes are opened by the Holy Spirit walk in the will of God.
Revelation by the Holy Spirit and prayer are the tools that should be used by every believer in order to successfully navigate this world. Without them we are blind. The Holy Spirit energizes these tools and makes them available.
Many times when we look at our situation from an Earthly/fleshly perspective we miss the true significance of the situation but when our eyes are opened by the Holy Spirit we have a different perspective.
In 2 Kings 6:14-17, the king of Syria sends his army to capture Elisha by night, in the morning Elisha's servant is dismayed when he sees the army surrounding the city. But Elisha asks the Lord to open his servant's eyes, and the mountain was full of horses and chariots of fire around Elisha.
Joseph interprets Pharaohs dream by the power of the Holy Spirit, for even Pharaoh declares in Genesis 41:38:
And Pharaoh said unto his servants, Can we find such a one as this is, a man in whom the Spirit of God is?
In Matthew 16:13-17, When asked by Jesus; who do men say that I am, Peter replies Elijah or one of the prophets but when asked who do you say that I am, Peter responds you are Christ, the Son of the living God. Jesus says flesh and blood has not revealed this to you but my Father.
In Acts 2:13-17, at pentecost, people they thought the believers were drunk when they prophesied in tounges, then Peter stood up to explain that this was the outpouring of the Holy Spirit as prophesied by Joel. Then Peter preaches about the gospel and the need for repentance, the men who thought the believers were drunk are convicted by the Holy Spirit and their eyes are opened to their own sinful condition, for they have crucified their Messaiah. They ask "Men and bretheren what shall we do?".
In John 9:2-3, When the disciples ask who sinned that this man was born blind? Jesus says neither he nor his parents but that the glory of God may be revealed.
Also, the apostle John was in the Spirit when the things in the book of Revelaton were shown to him.
Daniel 2:18
Daniel and his friends seek the mercies of God for revelation concerning Nebuchadnassar's dream. Also, Daniel prays for the return of the Jewish people, from the captivity reveelation concerning it is given to him by the angel in response to his prayer.
By reading the work of God to Jeremiah Daniel determines that the time of their return is near.
We should also remember that just as these truths are revealed to us through the Holy Spirit they might also be concealed from men by God.
During His ministry Jesus taught many things in parables, but then subsequently explained them to His disciples.
Luke 8:10, And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables, that seeing they might not see, and hearing they might not understand.
Those of us who have been saved by the grace of God through faith in Jesus are very fortunate that God has revealed to us the meaning of the gospel and His plan of salvation. Not everyone is so fortunate.
Romans 11:7-8:
7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded
8 (According as it is written, God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear) unto this day.
But for us believers the following holds true:
Romans 8:14, For as many as are led by the Spirit of God they are the sons of God.
Therefore having been blessed with insight from the Holy Spirit we should make use of this grace to serve God.
Romans 12: 1 - 2
1 I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.
2 And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.