Gal.3.16

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.

Gal.3.16

Now, the promises were made to Abraham and to his descendant. You will observe that Scripture, in the careful language of a legal document, does not say "to descendants," referring to everybody in general, but "to your descendant" (the noun, note, is singular), referring to Christ.

Gal.3.16

The promises were spoken to Abraham and to his seed. The Scripture does not say "and to seeds," meaning many people, but "and to your seed," meaning one person, who is Christ.

Gal.3.16

God gave the promise to Abraham and his child. And notice that it doesn't say the promise was to his children, as if it meant many descendants. But the promise was to his child--and that, of course, means Christ.