I think it’s pretty plain to see in the passage that, the Holy Spirit is the one who saves us, He is the only one fitting and sufficient to do it, being He is the Spirit of truth.
these things God has revealed to us through the Spirit. For the Spirit searches everything, even the depths of God. For who knows a person's thoughts except the spirit of that person, which is in him? So also no one comprehends the thoughts of God except the Spirit of God. 1 Cor 2
The Holy Spirit, knows all the secret things of God because He is God. The Spirit also reveals them to whom He pleases.
No one has ever seen God; the only God, who is at the Father's side, he has made him known. John 1:18.
Agree so far?
Since man can only know the secrets of man, only the Holy Spirit can do it. Man cannot know Gods secret thoughts, but only His own Spirit. And the Spirit alone reveals to man what is needed for their salvation.
Yes, man shares the gospel and the Holy Spirit uses the gospel in His work of salvation. Man can hear it, but unless the Spirit reveals it to man, it just falls at the wayside.
Now we have received not the spirit of the world, but the Spirit who is from God, that we might understand the things freely given us by God. And we impart this in words not taught by human wisdom but taught by the Spirit, interpreting spiritual truths to those who are spiritual. 1 Cor 2
you see, man can only understand worldly things, he cannot understand spiritual things. But the Spirit reveals these things to us, He is the only teacher of spiritual things.