Actually it is a biblical word and very important one at that.
Titus 3:5 He saved us, not on the basis of dees which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit.
John 3
John 6:63 It is the Spirit who gives life; the flesh profits nothing;
1 Peter 1:23-25 for you ave been born again not of seed which is perishable but imperishable, that is, through the living and enduring word of God.
Eph 2:4-5 But God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved)
1 Peter 1:3 Blessed e the God and Father of our Lord Jesus Christ, who according to His great mercy has caused us to be born again to a living hope through the resurrection of Jesus Christ from the the dead.
John 1:12-13 But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.