Justin Bieber with his wife Hailey Baldwin. (Instagram)

Justin Bieber has admitted he still has "love" for Selena Gomez but his wife Hailey Bieber is the "best thing" to ever happen to him.

The 'Never Say Never' hitmaker lashed out at an Instagram user who claimed he was "not in love" with his wife and only married the model to "get back" at his ex-girlfriend.

In response, Justin branded the user, who goes by the handle jaileyisajoke and had commented on a photo he'd shared of his wife, "immature" and insisted the 'Drop the Mic' presenter is the "best thing" to have ever happened to him, though he acknowledged he still has "love" for the 'Come and Get It' hitmaker.

He blasted: "Ur immature the fact that you have an account dedicated to dissing my wife and I is absolutely absurd why would I dedicate my whole life to someone in marriage to get back with my ex.

"Anyone who believes this is mean spirited or 10 years old or younger because a logical person doesn't talk or think this way you should be ashamed of yourself really.

"I absolutely loved and love Selena she will always hold a place in my heart, but I am head over heals in love with my wife and she is absolutely the BEST THING that has ever happened to me period.(sic)"

The 25-year-old singer admitted he didn't want to give such negative posts his "energy" and vowed never to respond to similar unkind messages again.

He continued: "The fact that you want to spend your day dedicating yourself to hate says a lot about you, and if this was some sick ploy to get my attention you are wrong on so many levels. 

"I've seen multiple people say things like this and ill never respond again to a message like this because I don't like to even give it my energy but this is a reply to all immature sick people who send Hailey hurtful messages like 'he always goes back to Selena' or 'Selena is better for him' YOU HAVE NO IDEA MY LIFE AND WHAT'S GOOD FOR ME!! (sic)"

And Justin insisted anyone who didn't support his relationship with Hailey couldn't be a real "fan".

He added: "Hayley is my bride period if you don't like that or support that that means you don't support me and if you don't support me you're not a fan nor a good person.

"If you were raised right your parents would have said if you don't have something nice to say don't say anthing.(sic)"