Scott Morrison started the week with a speech on security, but on Tuesday he started the parliamentary year with a psalm.
"Let Your compassion come to me that I may live, for Your law is my delight," the prime minister read at the annual church service to mark parliament's return.
Politicians have returned to Canberra for the first of three sitting weeks scheduled before the likely May election, with Labor under pressure over asylum seeker medical transfers.
Opposition Leader Bill Shorten said it was possible for Australia to have strong borders and treat refugees humanely.
"The current government confuses stubbornness with strength," he told reporters outside the Canberra church.
The latest polls show Labor is heading for a solid victory at the next federal election, but Mr Morrison told a joint coalition party room meeting they had a chance.
"Our opponents have plans that will make Australia weaker, to weaken the economy, to weaken our borders," Mr Morrison said.
"You can't pay for services with money that's not there, and we all know that Labor cannot manage money."
Liberal senator Arthur Sinodinos returned to parliament after more than a year spent fighting cancer, and he told coalition MPs the election could be won.
"There is a real fighting spirit out there, a view that we can win this," he said.
But he warned the Nationals leader and deputy prime minister not to repeat his Elvis impersonation efforts on morning television.
"Michael McCormack, no more singing, stick to your day job," he said to laughter from other MPs.
Labor is expected to push for an extra two sitting weeks to be added to the calendar to deal with legislation arising out of the banking royal commission.
The Senate will look at some legislation dealing with recommendations from the royal commission, while the lower house will consider laws making it compulsory for candidates to reveal if they are eligible to sit in parliament.
Manager of Opposition Business Tony Burke has also told the coalition that Labor will not pair MPs - a practice when opposition MPs sit out votes when a government member can't make it - in certain instances, to ensure numbers are even.
This will put pressure on the government for votes that require an absolute majority of 76 members, such as the legislation to bring asylum seekers to Australia for medical reasons.