"Jacob settled in the land where his father sojourned" (Genesis 37:1). Rabbi Levi Yitzchak of Berditchev opens his commentary on the Joseph story by explaining why Jacob lived in a state of constant anxiety, and why that anxiety was actually a sign of his greatness.
Nachmanides established a principle: even though God made numerous promises to Jacob, Jacob continued to fear that his sins might cause those promises to be voided. This was not a lack of faith. It was the highest form of faith: the recognition that serving God is a 24-hour obligation, and that any lapse, even an unconscious one, could have consequences.
The Talmud captures this tension with the phrase shema yigrom ha-chet (שמא יגרום החטא), "perhaps sin will intervene." A person can have complete faith (emunah) yet still lack confidence (bitachon) that the promise will be fulfilled, because confidence depends on one's ongoing worthiness.
Proper service of God, Rabbi Levi Yitzchak adds, requires joy. Not the joy that comes from comfortable circumstances, but a joy that infuses the entire personality, body and soul, with gratitude for the privilege of serving the Creator. This is something the angels achieve effortlessly, since they are disembodied beings without the distractions of physical existence. For human beings, it requires constant effort.
When Joseph's dreams of dominion provoked his brothers' murderous jealousy, it was not random family dysfunction. It was the eruption of a cosmic drama. The Mishnah (the earliest code of rabbinic law) teaches that everything God created was designed for His honor (Avot 6:10). Even sitting down to eat must be directed toward serving the Creator. When this consciousness slips, when a person forgets to elevate the mundane, trouble follows. Jacob's settling in the land was meant to be a time of spiritual completion. Instead, it became the prelude to exile, because the work of elevation is never finished.