Deuteronomy 28:45
Moreover all these curses shall come upon thee, and shall pursue thee, and overtake thee, till thou be destroyed; because thou hearkenedst not unto the voice of the LORD thy God, to keep his commandments and his statutes which he commanded thee:
This belongs to the presentation in Deuteronomy 26-28 of blessings for obedience and curses for disobedience, read to the people by Moses. The curses for breaking the covenant are set in contrast with the blessings promised for keeping it. Obedience is for present and future good, bringing prosperity, while disobedience brings a curse.
All these curses will come upon the disobedient, and will pursue and overtake them till destruction, because they hearkened not unto the voice of the Lord their God to keep His commandments and His statutes which He commanded them. Disease and suffering are among the evils associated with breaking God's law. The curses pursue and overtake until destruction.
The voice speaking there is Christ from the enfolding pillar of cloud, commanding that the statutes and judgments be kept with all the heart and all the soul. The directions express the principles of the law of the kingdom of God made specific, so that minds are not left in ignorance and uncertainty. God's promises are upon condition of obedience: keeping His judgments, commandments, and statutes brings life, prosperity, and blessings, while transgression brings a curse. God sends prosperity or adversity according to obedience or transgression of His law.
God erected barriers in His commandments and statutes to preserve health and holiness and to teach obedience. Obedience to the voice of God brings healing and protection from the diseases of Egypt. Breaking down those barriers removes that protection, so disease and suffering come through transgressing God's law and the curses pursue and overtake till destruction. Possessing the ark does not protect those who profane the law contained in it.
This explains why the adults of the army that left Egypt were refused entry into the promised land. God alters His purpose toward His people when they disobey. People must choose whether to suffer the consequences of transgression or enjoy the blessings of obedience. The curse on the earth and its inhabitants has grown heavier through continued transgression.
The directions lay a never-ceasing obligation on all blessed with life, health, and temporal and spiritual advantages. That includes gifts and offerings and the faithful tithe brought to the treasury to sustain messengers carrying light to those in darkness. The claims are just as binding and fresh now as God's gifts are fresh and continual, and the message has not grown weak because of age. The directions were repeated with Christ's own voice, calling followers to consecration and self-denial and self-sacrifice as the proof of true discipleship. Parents must teach children that work by denying needless trifles and presenting willing-hearted offerings that please the Lord like the widow's two mites.