I don't know exactly who
claims this in Word/Faith... but we claim this "in the Word." But as far as "Word/Faith" (believing in this truth)... is not
limited to only Word/Faith. There are possibly millions of believers all over the world (within) ALL faiths that embraces this also. Word/Faith from it's beginnings has most definitely (helped) carried the torch that led the way by the founding fathers of the movement to embrace and teach this truth.
God (absolutely) desires ALL believers/unbelievers (the entire planet) to receive
salvation,
healing, and
deliverance for the whole spirit, soul and body (sozo). He desired it so much that He offered the precious
blood of His only begotten son as the sacrificial lamb as (complete payment) for the sin debt that WE owed but couldn't pay.
Yes, even (faith talking) Christians do pass on prematurely but it's not from failure of God's Word for, "nothing is impossible for those who...
believe!"
Mark 9:22-23
And often it has cast him into the fire, and into the waters, to destroy him: but if you can do anything, have compassion on us, and help us. (What did Jesus say to him?) "What do you mean, 'If I can'?" Anything is possible for those who believes."
Lets back up a bit to...
(v17) A man in the crowd answered, "Teacher, I brought You my son, who is possessed by a spirit that has robbed him of speech.
(v18) Whenever it seizes him, it throws him to the ground. He foams at the mouth, gnashes his teeth and becomes rigid. I asked your disciples to drive out the spirit, but they could not."
(What then did Jesus say?)
(v19) Jesus answers him, and said, O faithless generation, how long shall I be with you? how long shall I suffer you? bring him to me. (Notice this was meant for His disciples also).
(v20) So they brought him, and seeing Jesus, the spirit immediately threw the boy into a convulsion. He fell to the ground and rolled around, foaming at the mouth.
(v21) Jesus asked the boy's father, "How long has this been with him?" "From childhood," he said.
(review v22 and v23 above)
(v24) Immediately the boy's father exclaimed, "I do believe; help me overcome my unbelief!"
(v25) When Jesus saw that the people came running together, he rebuked the foul spirit, saying to him, You dumb and deaf spirit, I charge you, come out of him, and enter no more into him.
So, the end result was this boy was "healed, and delivered." (the word sozo again). I hope this answers your questions. The disciples couldn't do it (they didn't believe), So Jesus did... and today, the body of Christ can and are doing it. (the ones that believe).
Be Blessed...