ViewData ["ErrorMessage"] does not appear in view

Hello, I'm new to the C # language and would like to know why my ViewData ["ErrorMessage"] does not appear in my view. Controller:

ViewData["ErrorMessage"] = "O e-mail digitado já se encontra registrado em nossa base de dados.";
return RedirectToAction("Index","Home");

View:

 <form asp-controller="Account" asp-action="Visitante" method="post" class="form-horizontal" role="form">
            @if (ViewData["ErrorMessage"] != null)
            {
                @ViewData["ErrorMessage"];
                <br />
            } 
            <div asp-validation-summary="ValidationSummary.All" class="text-danger"></div>
            <div class="form-group">
                <div class="col-md-6">
                    <input asp-for="Nome" class="form-control" placeholder="Nome" />
                    <span asp-validation-for="Nome" class="text-danger"></span>
                </div>
                <div class="col-md-6">
                    <input asp-for="Sobrenome" class="form-control" placeholder="Sobrenome" />
                    <span asp-validation-for="Sobrenome" class="text-danger"></span>
                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">
                    <input asp-for="Email" class="form-control" placeholder="E-Mail" />
                    <span asp-validation-for="Email" class="text-danger"></span>
                </div>
            </div>
            <div class="form-group">
                <div class="col-md-12">
                    <input type="submit" class="btn btn-default" style="width: 100%" value="Cadastre-se agora!" data-toggle="tooltip" data-placement="bottom" data-original-title="Cadastre-se" />
                </div>
            </div>
        </form>

See that in my view I make a @if to check if my ViewData is null, if not I want it to display the message, but from what I see ViewData does not contain the phrase I assigned no controller.

Thank you.