Why would the Holy Spirit need to contemplate the deep thoughts of God the Father and God the Son when the Holy Spirit Himself is God? The answer requires us to examine part of the Holy Spirit’s mission subsequent to the substitutionary atonement.
According to Jesus, the Holy Spirit began receiving guidance from the Father and the Son after He assumed the role of Counselor to mankind (John 16:7).
But when He, the Spirit of truth, comes, he will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come. He shall glorify Me; for He shall take of Mine, and shall disclose it to you. All things that the Father has are Mine; therefore I said, that He takes of Mine and will disclose it to you (John 16:13-15).
The Holy Spirit must absorb, assess and disseminate updated tactical and strategic information He receives from God the Father and God the Son.
“For to us God revealed them through the Spirit: for the Spirit searches all things, even the depths of God. (1 Cor 2:10).”
This is in addition to role of the Holy Spirit as implementer of prevenient grace. His primary responsibility as the emissary of prevenient grace is to call and convict each person (John 16:8). The Holy Spirit begins by calling your soul; you may choose to ignore the phone and let it ring. But until He senses a response in your heart He will go no further. If you eventually answer the call, He will try to awaken you to the idea that there is something wrong with your soul. As weeks and months go by while you ponder this thought, He is gradually drawing you closer to Himself. Then comes the hard part! You must confess your own sin nature and sinful behavior. You must confess that your heart, intellect and will are corrupt beyond measure. Only by acknowledging the poverty of your own soul can you enter the kingdom of God; those who are baptized with the Holy Spirit have a sense of absolute unworthiness. You must be convicted of your own sin nature and behavior. Without conviction, it is not possible to have true remorse in your heart. Without remorse, it is not possible to repent. Without repentance, there is no faith; belief must be preceded by repentance and followed by obedience to qualify as faith. Without faith, there is no obedience. Without conviction, remorse, repentance, faith and obedience, there is no salvation.
Conviction of sin is an unpleasant experience, particularly when you realize that, although God will forgive your sin, the consequences stand!