How were the Gentile nations supposed to come to know God?
The Gentile nations were to come to know God through Israel. God called Israel to be a kingdom of priests, and He would later funnel Israel back into the Gentile nations with the purpose of bringing them to a knowledge of their God. Until then, Gentiles remained outside the covenant promises, without hope and without God.
Les explains that out of the mainstream of humanity God called one little nation, Israel, and promised they would become a kingdom of priests. To prepare them, He placed them under the law and gave them temple worship, the priesthood, and the Old Testament. The Gentiles, however, were outside the covenant promises and not citizens of Israel; they were without hope and without God. They would continue on their way until such time as Israel could be funneled back into the Gentile nations with the idea of bringing them to a knowledge of their God. Les notes this is the whole scope of the Old Testament, which tells future events in subdued, latent terms that people did not comprehend.