Who are the sons of God?

Only those that believe on His name and who are born of God can be called sons of God.

We are His children if we are born again of the Spirit...

But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: [13] Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God. John 1:12-13

Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. [5] Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. [6] That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. [7] Marvel not that I said unto thee, Ye must be born again. [8] The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.

John 3:3,5-8

For as many as are led by the Spirit of God, they are the sons of God. Romans 8:14

For it is God which worketh in you both to will and to do of his good pleasure. [14] Do all things without murmurings and disputings: [15] That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world; Philippians 2:13-15

Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not. [2] Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is. 1 John 3:1-2

Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: [23] Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever. 1 Peter 1:22-23

Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him. [7] Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous. [8] He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil. [9] Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God. [10] In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother. For this is the message that ye heard from the beginning, that we should love one another. 1 John 3:6-11

Beloved, let us love one another: for love is of God; and every one that loveth is born of God, and knoweth God. [8] He that loveth not knoweth not God; for God is love. [9] In this was manifested the love of God toward us, because that God sent his only begotten Son into the world, that we might live through him. [10] Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins. [11] Beloved, if God so loved us, we ought also to love one another. 1 John 4:7-11

Whosoever believeth that Jesus is the Christ is born of God: and every one that loveth him that begat loveth him also that is begotten of him. [2] By this we know that we love the children of God, when we love God, and keep his commandments. [3] For this is the love of God, that we keep his commandments: and his commandments are not grievous. [4] For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith. [5] Who is he that overcometh the world, but he that believeth that Jesus is the Son of God? [6] This is he that came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth. 1 John 5:1-6

And he said unto them, Go ye into all the world, and preach the gospel to every creature. [16] He that believeth and is baptized shall be saved; but he that believeth not shall be damned. [17] And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues; [18] They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover. Mark 16:15-18

And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: [15] That whosoever believeth in him should not perish, but have eternal life. [16] For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. [17] For God sent not his Son into the world to condemn the world; but that the world through him might be saved. [18] He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. [19] And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. [20] For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. [21] But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. John 3:14-21

And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment. 1 John 3:23

These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God. 1 John 5:13