The 25-year-old singer and his 22-year-old model wife are happier together than ever as they prepare to celebrate their marriage with a second ceremony, one year after tying the knot.
A source told PEOPLE: "Despite some hard days, they really are two kids who are crazy in love. Hailey has a sweet, pure heart and her life is simple and uncomplicated.
"That's something Justin has craved for a long time whether he knew it or not. Hailey brings stability to his world, and she truly just wants to build a loving, happy home and family with Justin."
The pair originally tied the knot at a New York City courthouse last year but their second ceremony will focus more on their faith.
The insider said: "Their marriage is rooted in their faith. When things get difficult, they lean on their pastors and church friends.
It was previously revealed that Justin and Hailey were excited to celebrate their marriage in front of friends and family in South Carolina.
An insider said: "They are also very excited to have a celebration and party with family and friends. They've never had everyone together in one place so they are excited about that. They are looking forward to having friends and family get to know each other throughout the weekend. They have several different events planned and hope that people will have a great time."
The guest list for the wedding is being kept under wraps, but it has been reported Daniel Caesar will perform at the wedding while Hailey's father Stephen Baldwin will walk the model down the aisle.
A source said: "Kourtney Kardashian and Kendall Jenner are planning on attending the wedding and they have invited several key members of their church. Guests will be family and close friends/close church friends only. It's going to be very intimate."