Yes God promised Abraham a believing seed Gen 17:2-8
2 And I will make my covenant between me and thee, and will multiply thee exceedingly.
3 And Abram fell on his face: and God talked with him, saying,
4 As for me, behold, my covenant is with thee, and thou shalt be a father of many nations.
5 Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee.
6 And I will make thee exceeding fruitful, and I will make nations of thee, and kings shall come out of thee.
7 And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.
8 And I will give unto thee, and to thy seed after thee, the land wherein thou art a stranger, all the land of Canaan, for an everlasting possession; and I will be their God.
The Land of Canaan is Heaven ! Abraham looked for a Heavenly Land and his Heirs Heb 11:9-10,16
9 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:
10 For he looked for a city which hath foundations, whose builder and maker is God.
16 But now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city.
This is their inheritance, to Abraham and his seed. Heaven was a promise to them. Its not an offer, thats heresy !