How do Old Testament events like Isaac's offering relate to the New Testament?
Old Testament events such as Isaac’s offering were previews of what took place in the New. As Abraham laid Isaac on the altar and Isaac obeyed without struggling, so God did not spare His Son but gave Him up to be crucified, and Jesus was obedient unto that kind of death.
Les explains that many Old Testament things were just a preview of what took place in the New. Abraham laying Isaac upon the altar pictures God not sparing His Son but letting Him be crucified, mishandled, misused by the powers then in vogue, and given up. Isaac did not struggle or fight back; in complete obedience he let Abraham lay him upon the altar. Likewise, as Philippians shows, the Lord Jesus Himself was obedient unto that kind of death.