John Luke Robertson is enjoying his engagement to Mary Kate McEacharn and he's laying his values on his sleeve – sex should be part of a God-centred marriage.

The couple have yet to announce a date but they've been pretty open these last few weeks about what their marriage will look like when it comes.

On his Twitter yesterday, John Luke shared a post with some statistics about marriage claiming that 83 per cent of couples who don't have sex before they are married go on to have successful marriages, while 85 per cent of "active God-centred marriages" are successful.

The statistics are not sourced but John Luke was in agreement with them, saying: "Good stuff."

The Duck Dynasty star recently told FOX411 that the priority for his relationship with McEacharn is God.

"We said in the beginning when we started dating that if our relationship is not centered on God and if we're not encouraging one another to stay faithful and to just love people then we have no relationship at all," he told the network.

McEacharn meanwhile said that prior to dating Robertson she had been "just waiting and thought God would send someone to me".

"I was just very particular whenever it came to who I would date and I had to get to know him first and see if he was up to my standards," she told FOX411.

The couple met at summer camp four years ago and they were later placed next to each other in chemistry class at school.

Robertson previously told Us Weekly that their shared faith in Jesus was a big part of their relationship, and he went as far as to say McEacharn "never gave me the time of day until I started talking about Jesus".

As for the critics who say the teenagers are too young to marry, Robertson isn't really bothered what they think.

"Everyone has said something about us getting married too young and I think pretty much all of them are unmarried," he said.