William Branham taught that salvation (and healing) only lasts as long as your faith lasts. He also believed that you could have the Holy Spirit and go to hell.
What the Bible teaches
In his letter to the Ephesian church, Paul states:
- In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.
A person who believes in Christ are sealed with the Holy Spirit, and that sealing is until the day of their redemption:
- And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
It is impossible to lose your salvation in the same way it’s impossible to stop being your parents’ child. You are children by birth. Once you are born, you are born. Even if you are not acting like a well-behaved child, you are still a child because you are a child by birth. Similarly, you don’t hold on to God, God holds on to you. If a parent is holding a kid’s hand, even when that kid lets go, he is still connected to their parent because the parent is still holding on.
- And I will ask the Father, and he will give you another Helper, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you.
Furthermore, the author of Hebrews states:
for he has said, “I will never leave you nor forsake you.” 
If you read it in the English translation, Hebrews 13:5 says, “I will never leave you. I will never forsake you.” I hate almost every English translation, because in the Greek there are two negatives in the first clause and three negatives in the second clause. What God is saying to those upon whom he has put his grace, those whose relationship with him is not based on the legs of a man or on the strength of a horse but on his sovereign grace and his action, “I will never, ever detach myself from you. I will never, ever, ever forsake you.” 
Quotes of William Branham
Somebody says, "How does Divine healing... Is it... Does it last all the time?" It lasts just as long as faith lasts. And salvation lasts the same way, just as long as faith lasts. When you feel that you're not saved any more, you're not saved. For it's by faith are you saved through grace. Is that right?
Oh, brother. Some men so narrow-minded, you put a pencil between their eyes it'd blind them. That's right, so narrow- sighted... Sure. Salvation is--lasts as long as faith lasts. And Divine healing lasts as long as faith lasts.
The choice of your conduct. You could… You can't mix it now. You're either for God or against God, and the outward expressions shows exactly what's on the inside. See? The cocklebur… Many of you think, "I got the baptism of the Holy Ghost, I'm going to Heaven." That don't mean one thing that you're going to Heaven. No, sir. You can have the baptism of the Holy Ghost every hour in your life, and still be lost and go to hell. The Bible says so. Uh-huh, that's exactly right.
- ↑ The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2001), Eph 1:13–14.
- ↑ The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2001), Eph 4:30.
- ↑ Tony Evans, Tony Evans’ Book of Illustrations: Stories, Quotes, and Anecdotes from More than 30 Years of Preaching and Public Speaking (Chicago, IL: Moody Publishers, 2009), 258.
- ↑ The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2001), Jn 14:16–17.
- ↑ The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2001), Heb 13:5.
- ↑ Timothy J. Keller, The Timothy Keller Sermon Archive (New York City: Redeemer Presbyterian Church, 2013).
- ↑ MINISTRY EXPLAINED MINNEAPOLIS.MN 50-0711
- ↑ THE INTER VEIL STURGIS.MI 56-0121
- ↑ Leadership, 65-1207