Joni Eareckson Tada is as surprised as anyone else to have the song she voiced, Alone Yet Not Alone, nominated for an Oscar.

The original song was written as the theme for the upcoming faith-based movie of the same title due for release on 13 June.

Tada, a quadriplegic evangelist, was invited by the film's producer to sing the song after hearing her sing hymns at the closing session of the National Religious Broadcasters' Convention.

The little known film and song have been thrust into the limelight after the surprise nomination for the Academy Award's Best Original Song.

Tada had not anticipated receiving any acclaim for lending her voice to the song and was merely looking forward to the film coming out in the theatre.

"When I heard the simple, melodic ballad, I wanted to record it. I really resonated with the words – after all, I sit down in a stand-up world and often feel 'alone'," says Tada, who has been wheelchair-bound since the age of 17, when a diving accident left her paralysed from the neck down.

"But of course with my faith in God, I'm never really alone!" she continues.

"The Bible is filled with stories of God picking ill-equipped, unskilled people for places of great influence, which is how I feel, as a quadriplegic, singing an Academy Award-nominated song."

The faith-based film Alone Yet Not Alone is set in 1755 and tells the story of two young sisters who are kidnapped by Delaware Indians during the French and Indian War. It is their faith and a family hymn – "Alone Yet Not Alone" – that help them stay strong and endure such hardship.

Tada hopes the song will further God's work, especially for other people living with disability.

"Can you imagine how this might encourage other people with disabilities? It's all about 'God's power in our weakness,' and I love the chance to advance that message," she said.

Watch the trailer for the movie Alone Yet Not Alone here: