Deuteronomy 7:12, Because you listen. This verse shows the conditional nature of the Mosaic Covenant. Blessings are conditional upon obedience to YHVH’s Torah instructions in righteousness. It was a person’s choice to obey or not. Either way, the law of cause and effect would come into play. Blessings for obedience and curses for disobedience.
The same is true with the New Covenant. If we place our faith in Yeshua the Messiah,who is the Living Torah, and love him by keeping his commandments (John 14:15), we will not only be blessed physically blessed here and now, but we will be blessed with eternal life. Those who refuse to place their faith in Yeshua and obey his commandments will receive the fruit of their disobedience now, and will also perish in the lake of fire.
The law of cause and effect still applies to both the Mosaic Covenant and the New Covenant, and humans will reap the consequence of their actions based on the choices they make whether good or bad. It’s that simple.