Being born again, saved, becoming a Christian - whatever you call it - all begins with the fact that Jesus died for us on the cross to bring us back into a relationship with the Father in heaven. Sin separates us from God.
For all have sinned and fall short of the glory of God. ~ Romans 3:23 NIV
But God demonstrates his own love for us in this: While we were still sinners, Christ died for us. ~ Romans 5:8 NIV
We are saved by grace through faith alone in Jesus Christ by the Gospel - His death, burial, and resurrection. Man cannot save himself through good works, human efforts, or through faith in any other person, thing, or doctrine apart from the truth of Scriptures. Salvation is a gift from God, not of any human efforts. Man’s first step toward salvation is godly sorrow that leads to repentance of sin. The new birth is necessary for all men and when fulfilled produces eternal life. Justification is God’s gracious and full acquittal upon principles of His righteousness of all sinners who repent and believe in Christ. Justification brings the believer into a relationship of peace and favor with God (Ephesians 2:8-9; Galatians 2:16, 3:8; Titus 3:5; Romans 10:9-10; Acts 16:31; Hebrews 9:22).