The promises of Abraham are fulfilled in Christ

Because of Abraham’s obedience, God promised him that He will multiply His seed [offspring] as the starts of heaven, and as the sand upon the sea shore, and that his seed shall possess the gate of his enemies.

"That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy seed shall possess the gate of his enemies; and in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice." - Genesis 22:17-18 KJV

The promises of Abraham are fulfilled in Christ.

"Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. ... For ye are all the children of God by faith in Christ Jesus. For as many of you as have been baptized into Christ have put on Christ. ... And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise." - Galatians 3:16, 26-27, 29 KJV

"And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it." - Matthew 16:18 KJV

"But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth." - Acts 1:8 KJV

"Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call." - Acts 2:38-39 KJV

"And I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunderings, saying, Alleluia: for the Lord God omnipotent reigneth. Let us be glad and rejoice, and give honour to him: for the marriage of the Lamb is come, and his wife hath made herself ready. And to her was granted that she should be arrayed in fine linen, clean and white: for the fine linen is the righteousness of saints." - Revelation 19:6-8 KJV