When Jesus died on the cross, there was a great exchange: our sins were placed on Christ so that His righteousness would be placed on our account by faith. This is how people are made right before God. This is God's method of dealing with the guilt of our sins.
God is infinitely holy. In his wisdom and mercy he became man in the person of Jesus. He lived a perfect life so that he could die in the place of sinners and give us his righteousness. At the cross God put our sins on Jesus and punished him so that we don't have to experience an otherwise inevitable and painful eternal consequence of dying with unforgiven sin. He bore the punishment for our sins. The Bible says "All of us like sheep have gone astray, Each of us has turned to his own way; But the LORD has caused the iniquity of us all To fall on Him." (Isaiah 53:6, NASB). God accepted Christ's sacrificial death as payment for sins. Three days after his death he rose triumphantly from the dead.
The moment we place true faith in Christ, our sins are forgiven and God treats us as if we had lived Christ's perfect life. In this way God covers us with Christ's righteousness.
When we place our trust in Christ we become, very literally, "born again." We experience new life--new in time and new in quality. Through this new life God begins to change our thoughts, desires, and interests. He gives us His Spirit to empower and enlighten us.
The way God imparts faith and new life is through His Word, the Bible. The Bible has life (John 6:63, Hebrews 4:12); if we hear it and receive it, believe and obey it then we have the assurance that we too, have life. Hearing God's word with faith is the means to forgiveness and new life (Ephesians 1:13; Galatians 3:2; John 6:29). All of us will one day be judged by the Lord Jesus Christ, and we will be judged by how faithfully we responded to the Bible (John 12:48).
God is calling people to respond to his offer of forgiveness and new life by turning from sin and receiving Christ into their hearts to be their Lord and Savior.
"But as many as received Him, to them He gave the right to become children of God, to those who believe in His name" (John 1:12, NKJV).