MVC3 Razor – using viewbag in controller and view

I am trying to create dynamic properties for my viewbag based on an if/else condition in my controller. What the viewbag displays will depend on my logic in the controller. In my view I try to call my viewbag with razor syntax but nothing renders to the page.

[HttpPost]
        public ActionResult EditUser(vw_UserManager_Model edituser)
        {
            UserManager.Models.vw_UserManager_Model model = edituser; 
            int outcome = 0;
                outcome = UserManager.DAL.EditUser(model);
                if (outcome == 1)
                {
                    ViewBag.Message = "Successfully edited user" + model.UserName;
                    ViewBag.Description = "Look below for full details.";
                    //ViewData["Message"] = "Successfully edited user" + model.UserName;
                    return RedirectToAction("showSuccess", model);
                }
                else
                {
                    ViewBag.Message = "Failure";
                    return RedirectToAction("showFailure", model);
                }
        }

#region successErrorHandling
        public ActionResult showError(List<string> ErrorMessage)
        {
            ViewBag.ErrorMessage = ErrorMessage[0];
            return View("ErrorMessageView");
        }

        public ActionResult showSuccess(vw_UserManager_Model model)
        {

            return View("SuccessMessageeView", model);
        }

I set two properties for viewbag, message and description. I do a redirect if successful or failure.

@model UserManager.Models.vw_UserManager_Model
<h2>@ViewBag.Message</h2>
<br />
<h4>@ViewBag.Description</h4>
<h2>
    SuccessMessageeView</h2>
<br />
User Created:
@using (Html.BeginForm())
{
    <ul>
        <li> <b>@Html.Label("Username:  ")</b>@Model.UserName</li>
        <li> <b>@Html.Label("Salutation:  ")</b>@Model.salutation</li>
        <li> <b>@Html.Label("Firstname:  ")</b>@Model.firstname</li>
        <li>  <b>@Html.Label("Lastname:  ")</b>@Model.lastname</li>
        <li> <b>@Html.Label("Email:  ")</b>@Model.email</li>
        <li> <b>@Html.Label("Group name:  ")</b>@Model.group_name</li>
        <li> <b>@Html.Label("Is active:  ")</b>@Model.isactive</li>
    </ul>
}

In my view I then call my viewbag but it doesn't render. Am I doing this incorrectly?