The law, signed by Gov. JB Pritzker late last year, would allow terminally ill adults age 18 and older with a prognosis of less than six months to live to request life-ending medication that they would administer themselves. Illinois would become the 12th state to permit medical aid in dying.
Cupich has filed a lawsuit challenging the law, one of three legal challenges filed this summer.
"By normalizing suicide and doing it to the extreme that we see here in this law, we feel as though that's a violation of people's rights, their constitutional privileges, and should be struck down," Cupich said.
Under the law, two doctors must diagnose a patient's terminal illness. A psychological evaluation is required to determine that a patient is "of sound mind," and both oral and written requests are required to help ensure the patient is not being coerced.
Supporters of the law say those requirements provide substantial safeguards.
"There are pages and pages in legislation of the guardrails," said Ed Yohnka of the American Civil Liberties Union of Illinois.
Despite those provisions, the Archdiocese of Chicago argues the law compels doctors to provide patients with information about assisted dying and its benefits. The church contends that requirement violates First Amendment protections for free speech and freedom of religion.
"They're the ones now who are being compelled to say things and do things that are against their faith," Cupich said.
The ACLU of Illinois disputes that interpretation, arguing the archdiocese is misreading the law's requirements for physicians.
"They don't have to mention the option, but they do have to at least acknowledge it if a patient asks," Yohnka said.
According to the ACLU, if a patient requests information and a doctor is uncomfortable discussing the assisted-dying option, another physician can step in.
Cupich said he is sympathetic to the pain and suffering experienced by terminally ill patients but believes assisted suicide is not the solution.
"The medical field understands this they believe pain can be dealt with in a humane way," he said.
The archdiocese is seeking a temporary restraining order and says it is confident a judge will grant the request early next week. Supporters of the law, including the ACLU of Illinois, maintain the measure is legally sound and say they are confident it will ultimately withstand court challenges.