Christ came the first time into men’s vision by coming on the plane of their senses; He comes the second time into men’s vision by lifting men up to His plane of spiritual comprehension. This coming of Christ involves a new birth, a new creation, a new kingdom. It means a new step in the evolution of man. … Many times, in many ways, He declares, I am ‘from above.’ He is born a natural man, and yet possesses the life of the kingdom next higher, and proceeds to lift the natural man by a new birth into the kingdom of the spiritual man. He is born the son of man and the Son of God, bridging the chasm with his own being. … And so, the Christ life takes the character, the soul, the spirit of the natural man, which have developed through the ages–takes them through a new birth, this time with man’s consent.

The new birth of the natural man into the kingdom of the spiritual man, the reborning of his personality, making him a child of God after the type of Christ, is the tap-root of Christianity, is the chief artery. Cut that and all is gone. Keep that and let the ‘new creature’ grow toward his fulness, then Christ is recreated, reincarnated in him, and through him He is manifest again among men.”

– Isaac K. Funk, D.D., L.L.D., (co-founder of Funk & Wagnalls Company),
The Next Step in Evolution, 1902.
– Quoted by Ralph Waldo Trine, In the Hollow of His Hand, 1919.

Now when He (Jesus) was asked by the Pharisees when the kingdom of God would come, He answered them and said,
“The kingdom of God does not come with observation;
nor will they say, ‘See here!’ or ‘See there!’
For indeed, the kingdom of God is within you.”

Luke 17: 20-21
The Bible, New King James version

It is indeed a new life, or birth into a new life; it is conversion and redemption combined, if you please, the moment any soul realises this one great central truth that Jesus brought within the realm of human knowledge and experience.

 – Trine, op. cit.