Updating iPhone 4 jailbreak?

My husband and I both have jailbroken iPhone 4 on nTelos. (Please, do not go through the legalities of jailbreaking as it is still legal and these were purchased way before Jan 26, 2013.) We had a store do them for us. What I want to know is how to update to the newest jailbreak and still be able to have our service without it reverting back to Verizon or Sprint. Anybody done this and had it work successfully?

Hi
don't do it. A lot of problems.

  • Will updating my iPhone apps affect my phone speed as how updating the Operating System (OS) will? Currently I'm using the iPhone 5s on iOS 8.3 I know if I were to update my phone to the latest OS I may notice some slowdown on my phone's performance, since it may not have the "muscle" to handle certain functions. Many apps now are optimised for iOS 9 and/or the 6th generation phones. Will my 5s' speed performance slow down if I update my apps? Will the app's performance slow down?
  • Will updating Iphone 3GS to ioS 6.0 ruin screw up my jailbreak? I don't know how to ask this… Sorry if my wording makes no sense. I have an Iphone 3GS, and I want to update it iOs 6.0, but won't that take the jailbreak or whatever off? And I will have to jailbreak it again?
  • What will happen if i don't backup my Iphone files after updating my Iphone? So i had an iphone 4 and i tried updating it to IOS 5.1 and after updating it told me to backup my files so i backed up and it is taking forever to back up it has been like an hour the bar did not even move it moved a little from the start. Can i chose not to backup will anything happen if i don't back up? I currently used 29.1 gb space in my iphone I only have one place to store my stuff 382 GB of 451 GB used
  • Jailbreak iOS 6.1? IPhone 3gs jailbreak? Any sites with a simple way to jailbreak iOS 6.1? I'm new to all this stuff so the simpler the better HAS to be able to jailbreak my iPhone 3gs jailbreak on ios 6.1