Strictly speaking, there is but one Person so linked to God by the genetic tie as to be "the Son of God." Hence He is "the only begotten son." His being is grounded on the Divine Nature and is without time limits. He is the eternal Son. All other beings are grounded not on the nature of God, but upon His will, within time limits. They are creatures. The Divine Logos is never spoken of in the Holy Scriptures as a creature. God is never called the creator, but the Father, of our Lord Jesus Christ. His sonship is unique and unshared by any other being in the universe.
Sonship to God, when applied to others, is figurative, as is also the Fatherhood of God.
What then is signified when an archangel, or a man, is called a son of God? There are several things in the relation of a human son to a father which might be the foundation of this metaphor, such as actual descent and possession of the identical nature — which we have disclaimed for all creatures — or resemblance, imitation, obedience, love; qualities which may be summed up in the word likeness. This likeness is both natural and moral. The natural likeness of the human creature to the Creator consists in personality, intelligence, a moral sense, implying freedom and spirituality, i.e., Spirit is the essential principle. The moral likeness exists when man possesses qualities like God's moral attributes, love, holiness, justice, wisdom and truth. But since the moral attributes eclipse the natural in excellence, likeness to God is predicated only of the possession of the moral qualities. Satan, though still like God in his natural attributes, is in no scriptural sense a son of God, because of his lack of the moral likeness.
This is true of all unregenerate men. They are not sons of God. Christ plainly told certain Jews that they were of their father, the devil, because they had taken on his moral characteristics. The very taproot of modern liberalism, universal salvation on the ground of the universal Fatherhood of God, lies in a neglect of these scriptural distinctions, and in making the divine Fatherhood natural and genetic, like human fatherhood, and in reasoning from the latter to the former on this wise, "as no human father would be so cruel as to banish his child from his presence forever, much less will the divine Father." The fallacy lies in the assumption, that a wicked man is a child of God, when he is really a child of Satan, because he has taken on his moral likeness. The writer of the epistle to the Hebrews declares that certain men "are bastards, and not sons." It will not do to literalize or carnalize the terms "son" and "Father," in speaking of man's relation to God. For the outcome will be universal salvation on the ground of a fondling sentimentalism, an unholy love on the part of God, instead of moral likeness to Him in holy character.
Another error is expressed in the maxim, "Once in grace, always in grace," based upon the idea, Once a child, always a child. Substitute, "Once like God, always like God," and the fallacy immediately stands out to view, for Satan once bore the moral image of his Maker. If sonship to God is pressed as a proof of the impossibility of becoming a son of perdition, why may not sonship to the devil be alleged to be an insuperable barrier to becoming a son of God?
Are our positions sustained by the Bible? We reply that in the New Testament sonship is the peculiar and distinguishing privilege of those who by faith receive Jesus Christ (John i. 12), and it consists in conformity to the image of the Son of God (Rom. viii. 29), and in no case do the words, "Sons of God," "Children," and "Father," indicate anything but a spiritual likeness.
Once, and once only, St. Paul, while preaching on Mars Hill, taking natural religion as his starting point, so as to stand on common ground with his pagan audience, speaks of the human race in the words of a Greek poet, as the offspring of God. Even here he is careful to limit the metaphor to likeness in those natural characteristics in which men consciously differ from "gold or silver or stone." For they are conscious of freedom and moral accountability.
In all the New Testament the terms "son," "child," "sonship," "adoption," and "Father," when applied to the relation of men to God, signify a spiritual likeness enstamped in outline by the Holy Spirit at that religious crisis figuratively called the new birth, and in completeness at the subsequent crisis of entire sanctification. Utterly foreign to the Gospels and the Epistles, and to apostolic preaching, as reported in the Acts of the Apostles, is salvation on the ground of the natural fatherhood of God. Such a doctrine would "make the cross of Christ of none effect," because it would be needless in the scheme of salvation.
— edited from Mile-Stone Papers Part 1 Chapter 2.