"The legalisation would give people the sovereignty over who lives and who dies, we, as Christians are against that.
"We believe that God is the only one who decides who lives or dies, from the womb to the other end of the spectrum."
In this year's general election, on October 17, people can vote in a referendum on whether they support the End of Life Choice Act 2019.
The Act gives people with a terminal illness the option of requesting assisted dying.
Parliament passed the End of Life Choice Act, but it has not come into force.
The Act will only come into force if more than 50 per cent of voters in the referendum vote "Yes".
Woodley said he sympathised with people who suffered in their latter years, but he said, compassionate care was "better than opening this door".
"I can see parents and grandparents being coerced by a younger generation who may not know the meaning of compassion and personal sacrifice for the benefit of others," Woodley said.
"Part of the call upon the human race is to look after each other. Our job is to ease pain compassionately.
"I think euthanasia will become the easy option for those who have ailing loved ones, but find their necessary care a burden, or people may be made to feel like they are a burden."
He said the other factor not talked about was that it may be tempting for children to desire an early departure of their parents or grandparents for their inheritance.
"This too could mean pressure on the elderly," he said.
"Therefore I am opposed to the deliberate extinguishing of anyone's life.
"Taking people off life support systems because they are clinically dead, brain dead and are living only through artificial means is understandable, but no one has the right to end a life which still has its full facilities operating.
"Only God decides."
