"There would be a huge elephant in the room" if Duggar returns to Arkansas for the holidays, a source tells PEOPLE

March 03, 2015 03:30 PM

Josh Duggar‘s family is thinking of him on his 28th birthday as he continues treatment in a faith-based rehab facility.

“Today is our son Josh’s birthday. The heartache of the past year cannot surpass the joy 28 years ago on this day when we first became parents!” Josh’s parents Jim Bob and Michelle wrote on the family’s official Facebook page Thursday. “We love you Josh and believe your best days can be ahead of you. We continue to pray for you every day.”

Josh checked into a faith-based rehab center in Illinois in late August after admitting he had been unfaithful to wife Anna and having a pornography addiction.

Josh shares children Marcus, 2, Mackynzie, 6, Michael, 4, and Meredith Grace, 7 months, with Anna, 27.

Josh’s sisters Jessa and Jill (Duggar) Dillard returned to TV with the three-part special Jill and Jessa: Counting On in December. The docuseries was picked up for a full season last month.

“Family is everything,” Jessa, 23, said in a trailer for the series, with sister Joy Anna, 18 adding, “2015 was a very difficult year.”