La sección de la Torá de esta semana habla de una promesa Divina: «Y será que si escuchan estas leyes y las cuidan y hacen, D-s tu Señor cuidará para ti el pacto […] y te amará y bendecirá y multiplicará».
Más tarde la Torá habla del lado opuesto: «Y será que si te olvidares de Di-s tu Señor […] se perderán»
It's very simple. If we observe His mitzvot, are careful with our words, etc., God does His part and blesses us. If not, He doesn't.
However, it's not that simple. To paraphrase the language of our sages, what does this resemble? A king of flesh and blood, whose son received detailed instructions on how to behave and failed to follow them. He was warned through advisors and those close to the king, but he didn't improve, or he improved temporarily and then regressed. This happened again and again. How does the story end? The king always gives another chance. Why? Because it's his son.
Likewise, we are the children of God. Yes, I know, all creatures are, but we are the firstborn, the chosen ones from among all humanity. There is always another opportunity. There is always a chance to do Teshuvah and return to God.
That's what Judaism is all about. God, our Merciful Father, always has another opportunity ready, always has his hand outstretched; it's up to us to take it.