Two thieves vandalised a church before stealing £146 from the vestry.
The raiders mingled with worshippers during a Sunday service, then re-entered Prestatyn Parish Church at around 0830 BST to steal the money.
They smashed the belfry door before fleeing in a stolen black VW Golf.
The Reverend Quentin Bellamy said: "It's a sad reality in this day and age for those of us in the ministry that we just don't know who is coming through the door."
One man was described as about 6ft (1.83m) with dark hair and large build. The other is around 5ft 9in (1.75m), had dark hair and was wearing dark clothes.
The stolen car was later found abandoned nearby.
A North Wales Police spokesman said: "This was a heartless theft.
"The two men attended the service at around 7.30am then left along with the rest of the congregation.
"They waited until everyone had gone and re-entered the open church as it was being prepared for the next service at 9.30am and stole the money.
"They also caused mindless damage to the door of the belfry."
Police are studying CCTV footage from outside the church.
Anyone with information can call 0845 6071001 (Welsh language), 0845 6071002 (English language) or Crimestoppers anonymously on 0800 555 111.