We are continuing to look at Abraham’s vision of the stars of heaven representing the people that would be influenced by his life of faith and trust in God. At an earlier time, the Lord had him look at the dust of the earth as a comparison:
I will make your offspring like the dust of the earth, so that if anyone could count the dust, then your offspring could be counted (Genesis 13:16).
The dust of the earth could be a picture of the natural seed of Abraham, the Jewish people, and the vision of the stars of the sky could represent the heavenly seed, those who are born again of the Holy Spirit, the Church of the Living God. In this sense, we see an earthly and a heavenly seed.
5And He took him outside and said, “Now look toward the heavens, and count the stars, if you are able to count them.” And He said to him, “So shall your descendants be.” 6Then he believed in the LORD; and He reckoned it to him as righteousness (Genesis 15:5-6 Emphasis mine).
Something happened within Abram's heart when he saw the grand vision of the stars of the sky. He was told that his offspring would be like the stars in number. Notice Abram's response to the vision: “Abram believed the LORD, and he credited it to him as righteousness” (v. 6). This faith in God was expressed before circumcision, and more than four hundred years before the Law and the Ten Commandments were given. The Lord saw that inside Abram's heart, there was a deep-seated trust and inner rest of belief applied to his heart, his inner being. On account of his faith, the Lord imparted to Abram the gift of righteousness credited to his spiritual bank account. W.H. Griffith Thomas, in his commentary on Genesis, writes:
“The original Hebrew for ‘believed’ comes from a root whence we derive our ‘Amen,’ and we might paraphrase it by saying that ‘Abraham said Amen to the Lord.’ ‘Amen’ in Scripture never means a petition (‘May it be so’), but is always a strong assertion of faith (‘It shall be so,’ or ‘It is so’).
In the world we live in, God still operates in the same way. When we hear the gospel of the finished work of Christ in paying our debt of sin upon the cross, and we believe in our heart that God raised Christ from the dead, the gift of righteousness is credited to our spiritual bank account, as it was to Abraham. No longer do we work at trying to please God by empty works, but we rest our souls on the finished work of God at the cross. The gospel (the good news) is that Christ has wholly restored the relationship between God and man through His substitutionary work in dying for us and as us on the cross. If you will place your life into His hands and merely believe (trust), just as Abram did, then you too will have credited to your spiritual bank account the righteousness of God. God gives us faith to reach out to Him and receive the gift of eternal life in Christ. God gave the gift of righteousness to Abram upon his trust and belief in God's Word to his heart, just as He does to all those who believe the gospel. Keith Thomas.
 W.H. Griffith Thomas, Genesis (Grand Rapids, MI: Eerdmans, 1946) p. 138.