Our text testifies that “He that hath the Son hath life.” Of course, by “life” here is meant not mere existence, or natural life; for we all have that whether we have the Son of God or no—in the image of the first Adam we are all created living souls, and continue in life until the Lord recalls the breath from our nostrils—but the life here intended is spiritual life, the life received at the new birth, by which we perceive and enter into the heavenly kingdom, come under new and spiritual laws, are moved by new motives, and exist in a new world. The life here meant is the life of God in the soul, which is given us when we are new created in the image of the second Adam, who was made a quickening spirit; a celestial form of life inwardly perceptible to the person who possesses it, and outwardly discernible to spiritual observers by its holy effects and heavenly fruits. This spiritual life is the sure mark of deliverance from the penal death which the sentence of the law pronounced. Man under the law is condemned, sentence of death is recorded against him; but man under grace is free from the law, and is not adjudged to death, but lives by virtue of a legal justification, which absolves him from guilt, and consequently liberates him from death. These two kinds of life, the life which is given by the judge to the offender when he is pardoned, and the life which is imparted from the divine Father, the heir of heaven is begotten again unto a lively hope—these two lives blend together and ensure for us the life eternal, such as they possess who stand upon the “sea of glass,” and tune their tongues to the music of celestial hosts. Eternal life is spiritual life made perfect. If we live by virtue of our pardon and justification, and if, moreover, we live because we are quickened by the Holy Spirit, we shall also live in the glory of the eternal Father, being made in the likeness of our Lord Jesus Christ, who is the true God and eternal life. This is the life here intended—life spiritual, life eternal.
– Charles H. Spurgeon