A representative verse is Romans 8:9 You, however, are controlled not by the sinful nature but by the Spirit, if the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, he does not belong to Christ, linking it interestingly to the other through theme, union with Christ. But the concept is best explained by Jesus in the gospel of John were he says to the interested Nicodemus; “I tell you the truth, no one can see the kingdom of God unless he is born again." (John 3:3) Not a physical rebirth but an inward work of the Spirit explains Jesus, who then in the following verses links this to a synopsis of the good news.
There are synergistic aspects of our salvation, for example faith, repentance and mortification. This means God uses secondary causes, such as trust, turning or putting-sin-to-death, as part of his saving action. But Regeneration is out of our control, it's monergistic, we don't summon up the Holy Spirit like a witch, he works in inside us like sap inside a tree. This is because our sinful inability prevents us from responding positively to God. But your iniquities have separated you from your God; your sins have hidden his face from you, so that he will not hear. (Isaiah 59:2)