Serving God goes beyond simply performing required actions; it is deeply tied to a person's emotional state and the attitude of their heart. The ultimate tragedy is missing one's spiritual purpose precisely during times of immense prosperity. The resulting destruction and exile did not stem solely from severe violations, but from a fundamental flaw in the quality of the service—specifically, the absence of joy.
The primary approach among commentators is that the central critique is not about abandoning God's service entirely, but rather going through the motions without happiness. Experiencing joy while fulfilling a Commandment is a requirement in its own right, carrying its own distinct reward. If people truly grasped the profound impact of their actions, they would perform them with overwhelming enthusiasm and gladness [רבנו בחיי]. Furthermore, while anyone dedicated to serving God will inevitably make mistakes, serving Him with joy awakens divine mercy. This joy neutralizes strict judgment and causes God to overlook those shortcomings. Ultimately, it was the absence of this joy that led to exile [חומש קה״ת].
This required state of happiness and a glad heart is understood in several ways. Some explain that it points specifically to the study of Torah, which naturally brings joy to the mind [שפתי כהן, אור החיים], as well as to the effort invested in truly understanding the details of positive Commandments [אור החיים]. Another perspective views this joy as an allusion to the singing of the Levites in the Temple, which stands as the ultimate expression of serving God with a joyful and glad heart [תורה תמימה].
A crucial element of this failure is the context of wealth and prosperity. The primary approach among commentators is that the failure occurred while living in the midst of abundance. The tragedy was neglecting to serve God properly while possessing wealth, capability, and every good thing [רש״י, מזרחי, שפתי חכמים, שטיינזלץ], with all needs and desires completely fulfilled [אבן עזרא, ביאור יש״ר]. This reality particularly characterized those who remained in the Land of Israel and had every reason to be happy and content in their homeland [העמק דבר]. Alternatively, the failure is seen not just as happening during a time of wealth, but as a failure of gratitude because of it. God provided overwhelming abundance, elevating the people above all others. Specifically because of this tremendous blessing, there was a deep obligation to recognize His goodness and serve Him joyfully [גור אריה, בכור שור].
The result of this ingratitude is an exact, measure-for-measure consequence. A person who abandons the service of God while surrounded by wealth and abundance will ultimately be forced to serve their enemies in a state of poverty and total deprivation [ביאור יש״ר, בכור שור]. The moment the Israelites cast off the responsibility of the Commandments, God removes His protection, leaving them vulnerable to the control of enemy nations and the harsh forces of nature [רש ר הירש, אור החיים].
Looking at the broader framework of these warnings, there is a striking difference between these consequences and those found earlier in the book of Leviticus. The earlier warnings were directed at the entire nation as a collective whole, which is why they conclude with words of comfort and a promise of redemption. In contrast, these warnings are directed at private individuals or specific groups within the nation who choose to do wrong. Because these consequences are aimed at individual sinners rather than the entire nation, they do not end with a promise of comfort. Divine comfort and the eternal memory of the covenant are always preserved for the nation as a whole, but they are not guaranteed to individuals who choose to abandon the path [אור החיים].