Winans, who also serves as a pastor at Detroit's Perfecting Church, will be leading Houston's private funeral at the New Jersey church where the singer performed as a child.
Winans told the Detroit Free Press that he felt like he had lost a sibling when he heard of Houston's sudden death on Saturday.
I'm OK. As well as could be expected, Winans said. This is like a sister. This is unbelievable, Winans said.
He reflected on his past with Houston, who he called nip from a young age.
(I've) been with Nip during the highs and the lows. I met Whitney Houston when she had her first record. There was a lot of potential. But you didn't know where she was headed, he said.
We both were at the William Morris Agency at the time. And we both had the same agent. And I knew of Whitney Houston. I knew of this phenomenal record. And you saw her picture back in the day everywhere. But I didn't know the songs and I didn't know her.
When Winans met Houston he said he knew she would instantly become like family.
Houston's mother and gospel singer Cissy Houston, asked Winans to deliver the eulogy on behalf of the family on Saturday.
Houston's funeral is invitation-only and will be attended by close friends and family. The Associated Press will live stream the entire service online.
Houston, 48, was found dead in a bathtub in a fifth-floor suite at the Beverly Hilton Hotel on Saturday. The cause of her death is unclear and is unlikely to be revealed anytime soon. Coroner's officials have said they will not release the results of the singer's autopsy as police detectives continue to investigate the death.
There were no indications of foul play, but rumors surrounding her death signal to the possibility of an overdose of prescription drugs. Houston has battled with drug and alcohol abuse for years.