1 Peter 2:10 KJVS
 Which in time past were not a people, but are now the people of God: which had not obtained mercy, but now have obtained mercy.
Years ago I read the above verse during a daily Bible reading. At the time it confused me. It is pasted below in context as apostle Peter wrote it in his epistle.
1 Peter 2:7-10 KJVS
 Unto you therefore which believe he is precious: but unto them which be disobedient, the stone which the builders disallowed, the same is made the head of the corner,  And a stone of stumbling, and a rock of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed.  But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:  Which in time past were not a people, but are now the people of God: which had not obtained mercy, but now have obtained mercy.
Apostle Peter was appointed to minister the gospel to the Jew, Gal 2:7&8, so how could those he was addressing ever be not the people of God? Up to that point in my life popular culture and even Christian teachings presented the Jew as God’s chosen people. So why did Peter say in time past they were not a people but are now the people of God? Then as time pasted I noticed these verses.
Romans 9:6-8 KJVS
 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:  Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.  That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
There are children of the flesh and children of the promise, and only the children of the promise are accounted for the seed. These verses cleared up some of my confusion. Which ultimately lead let me to Galatians.
Galatians 4:21-26,30-31 KJVS
 Tell me, ye that desire to be under the law, do ye not hear the law?  For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman.  But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise.  Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar.  For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children.  But Jerusalem which is above is free, which is the mother of us all.  Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.  So then, brethren, we are not children of the bondwoman, but of the free.
Verse 25 makes clear that Jerusalem of Jesus day were children of the flesh, sons of the bondwoman, which are the covenant of the law given to Moses on Mount Sinai. Rather than those of the covenant of promise. They will not inherit the world along with father Abraham, Gal 3:29. The words spoken by our Lord in the following verses demonstrates the distinction between the children of the flesh and the children of the promise. Both are Abrahams seed, but only some are children who were chosen to rule and reign with Jesus Christ , Eph 1:4.
John 8:37-39 KJVS
 I know that ye are Abraham’s seed; but ye seek to kill me, because my word hath no place in you.  I speak that which I have seen with my Father: and ye do that which ye have seen with your father.  They answered and said unto him, Abraham is our father. Jesus saith unto them, If ye were Abraham’s children, ye would do the works of Abraham.