In order to understand the meaning of this expression “children of Abraham,” we need to be acquainted with the life story of Abraham.
Abraham became one of the most important persons in the history of Israel. Born in Ur of the Chaldeans (located in the modern country of Iraq), he received a special call directly from the Lord: “Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will show thee: And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing: And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed. So Abram departed, as the LORD had spoken unto him; ….and Abram was seventy and five years old when he departed out of Haran,” Genesis 12:1-4.
When he received the divine call, Abraham revealed willing submission to God’s will. In Hebrews 11:8, we are told that he “obeyed; and went out, not knowing wither he went.”
However, his faith was not perfect. He revealed weak points in his character when he accepted the suggestion of Sarah, his wife, to have a child with her Egyptian servant, Hagar. He also demonstrated unbelief both times that he said that Sarah was his sister rather than his wife.
As a means to deepen Abraham’s faith in Him, and lead his servant to fully conquer unbelief, God called the patriarch to obey His instruction in the most terrible way: offer his son Isaac as a sacrifice on Moriah’s mountain.
“By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son. Of whom it was said, That in Isaac shall thy seed be called: Accounting that God was able to raise him up, even from the dead; from whence also he received him in a figure,” Hebrews 11:17-19.
The faith of Abraham was tested to the utmost, and in that test, he developed and deeper and total obedience to God’s voice.
The Bible says that the children of Abraham have the faith of Abraham and the works of Abraham. That is, they will obey Jesus, implicitly and completely.
"Even as Abraham believed God, and it was accounted to him for righteousness. Know ye therefore that they which are of faith, the same are the children of Abraham. And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed. So then they which be of faith are blessed with faithful Abraham. For as many as are of the works of the law are under the curse: for it is written, Cursed is every one that continueth not in all things which are written in the book of the law to do them" Galatians 3:6-10.
Abraham became the classic example of those who are justified by faith. He “believed God, and it was accounted to him for righteousness,” Galatians 3:6. Paul would use the history of Israel’s founding patriarch to urge his readers, including us, to experience and live in utter dependence upon God. Like Abraham, God is using the experiences of our life as seen through the light of His Word to develop faith in us.
“Our love to Christ will be in proportion to the depth of our conviction of sin, and by the law is the knowledge of sin. But as we see ourselves, let us look away to Jesus, who gave Himself for us that He might redeem us from all iniquity. By faith take hold of the merits of Christ, and the soul-cleansing blood will be applied. The more clearly we see the evils and perils to which we have been exposed, the more grateful shall we be for deliverance through Christ. The gospel of Christ does not give men license to break the law, for it was through transgression that the floodgates of woe were opened upon our world.” —Faith and Works, pp. 95, 96.
“There is a belief that is not a saving faith. The Word declares that the devils believe and tremble. The so-called faith that does not work by love and purify the soul will not justify any man. ‘Ye see,’ says the apostle, ‘how that by works a man is justified, and not by faith only.’ Abraham believed God. How do we know that he believed? His works testified to the character of his faith, and his faith was accounted to him for righteousness.
“We need the faith of Abraham in our day, to lighten the darkness that gathers around us, shutting out the sweet sunlight of God’s love, and dwarfing spiritual growth. Our faith should be prolific of good works; for faith without works is dead. Every duty performed, every sacrifice made in the name of Jesus, brings an exceeding great reward. In the very act of duty, God speaks and gives His blessing.” —Reflecting Christ, p. 79.
“Through type and promise God ‘preached before the gospel unto Abraham.’ Galatians 3:8. And the patriarch’s faith was fixed upon the Redeemer to come. Said Christ to the Jews: ‘Your father Abraham rejoiced that he should see my day; and he saw it, and was glad.’ John 8:56, R.V., margin. The ram offered in the place of Isaac represented the Son of God, who was to be sacrificed in our stead. When man was doomed to death by transgression of the law of God, the Father, looking upon His Son, said to the sinner, ‘Live: I have found a ransom.’
“It was to impress Abraham’s mind with the reality of the gospel, as well as to test his faith, that God commanded him to slay his son. The agony which he endured during the dark days of that fearful trial was permitted that he might understand from his own experience something of the greatness of the sacrifice made by the infinite God for man’s redemption. No other test could have caused Abraham such torture of soul as did the offering of his son. God gave His Son to a death of agony and shame. The angels who witnessed the humiliation and soul anguish of the Son of God were not permitted to interpose, as in the case of Isaac. There was no voice to cry, ‘It is enough.’ To save the fallen race, the King of glory yielded up His life. What stronger proof can be given of the infinite compassion and love of God? ‘He that spared not His own Son, but delivered Him up for us all, how shall He not with Him also freely give us all things?’ Romans 8:32.” —Patriarchs and Prophets, p. 154.
“To Abraham was given the promise that of his line the Saviour of the world should come: ‘In thy seed shall all the nations of the earth be blessed.’ ‘He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.’ Genesis 22:18; Galatians 3:16.” —The Acts of the Apostles, p. 222.
Abraham himself was to share the inheritance. The fulfillment of God’s promise may seem to be long delayed—for ‘one day is with the Lord as a thousand years, and a thousand years as one day’ (2 Peter 3:8); it may appear to tarry; but at the appointed time ‘it will surely come, it will not tarry,’ Habakkuk 2:3. The gift to Abraham and his seed included not merely the land of Canaan, but the whole earth. So says the apostle, ‘The promise, that he should be the heir of the world, was not to Abraham, or to his seed, through the law, but through the righteousness of faith,’ Romans 4:13. And the Bible plainly teaches that the promises made to Abraham are to be fulfilled through Christ. All that are Christ's are ‘Abraham's seed, and heirs according to the promise’—heirs to ‘an inheritance incorruptible, and undefiled, and that fadeth not away’—the earth freed from the curse of sin. Galatians 3:29; 1 Peter 1:4. For ‘the kingdom and dominion, and the greatness of the kingdom under the whole heaven, shall be given to the people of the saints of the Most High;’ and ‘the meek shall inherit the earth; and shall delight themselves in the abundance of peace,’ Daniel 7:27; Psalm 37:11.
“God gave to Abraham a view of this immortal inheritance, and with this hope he was content. ‘By faith he sojourned in the Land of Promise, as in a strange country, dwelling in tabernacles with Isaac and Jacob, the heirs with him of the same promise: for he looked for a city which hath foundations, whose builder and maker is God,’ Hebrews 11:9, 10.
“Of the posterity of Abraham it is written, ‘These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth.’ Verse 13. We must dwell as pilgrims and strangers here if we would gain ‘a better country, that is, a heavenly.’ Verse 16. Those who are children of Abraham will be seeking the city which he looked for, ‘whose builder and maker is God.’” —Patriarchs and Prophets, pp. 169, 170.
“God has made every provision whereby our thoughts may become purified, elevated, refined, and ennobled. He has not only promised to cleanse us from all unrighteousness, but He has made an actual provision for the supply of grace that will lift our thoughts toward Him and enable us to appreciate His holiness. We may realize that we are Christ’s possession and that we are to manifest His character to the world. Prepared by heavenly grace, we become clothed with the righteousness of Christ, in the wedding garment, and are fitted to sit down at the marriage supper. We become one with Christ, partakers of the divine nature, purified, refined, elevated, and acknowledged to be the children of God—heirs of God and joint heirs with Jesus Christ.” —Mind, Character, and Personality, vol. 2, p. 660.
“Without faith it is impossible to please God. Living faith enables its possessor to lay hold on the merits of Christ, enables him to derive great comfort and satisfaction from the plan of salvation.” —Selected Messages, vol. 1, p. 364.
"But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith. And the law is not of faith: but, The man that doeth them shall live in them. Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree," Galatians 3:11-13.
“The types and shadows of the sacrificial service, with the prophecies, gave the Israelites a veiled, indistinct view of the mercy and grace to be brought to the world by the revelation of Christ. To Moses was unfolded the significance of the types and shadows pointing to Christ. He saw to the end of that which was to be done away when, at the death of Christ, type met antitype. He saw that only through Christ can man keep the moral law. By transgression of this law man brought sin into the world, and with sin came death. Christ became the propitiation for man’s sin. He proffered His perfection of character in the place of man’s sinfulness. He took upon Himself the curse of disobedience. The sacrifices and offerings pointed forward to the sacrifice He was to make. The slain lamb typified the Lamb that was to take away the sin of the world.
“It was seeing the object of that which was to be done away, seeing Christ as revealed in the law, that illumined the face of Moses. The ministration of the law, written and engraved in stone, was a ministration of death. Without Christ, the transgressor was left under its curse, with no hope of pardon. The ministration had of itself no glory, but the promised Saviour, revealed in the types and shadows of the ceremonial law, made the moral law glorious.
“‘We all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory even as by the Spirit of the Lord.’ Christ is the sinner’s advocate. Those who accept His gospel behold Him with open face. They see the relation of His mission to the law, and they acknowledge God’s wisdom and glory as revealed by the Saviour. The glory of Christ is revealed in the law, which is a transcript of His character, and His transforming efficacy is felt upon the soul until men become changed to His likeness. They are made partakers of the divine nature, and grow more and more like their Saviour, advancing step by step in conformity to the will of God, till they reach perfection.
“The law and the gospel are in perfect harmony. Each upholds the other. In all its majesty the law confronts the conscience, causing the sinner to feel his need of Christ as the propitiation for sin. The gospel recognizes the power and immutability of the law. ‘I had not known sin, but by the law,’ Paul declares. The sense of sin, urged home by the law, drives the sinner to the Saviour. In his need man may present the mighty arguments furnished by the cross of Calvary. He may claim the righteousness of Christ; for it is imparted to every repentant sinner.” —The Seventh-day Adventist Bible Commentary, vol. 6, p. 1096.