Reenter the new password in configured Gmail account
Some options:


Try hitting Menu -> Refresh in GMail, there should be a notification prompting you to re-enter the password.  If it's in the notification bar, pull it down and click it.
Clear the cache and data for all Google apps on your phone: Gmail, Gmail storage, Google Framework Services, Talk, Accounts, Play Store, etc. via Settings -&gt; Applications -&gt; Manage applications -&gt; All.
If your phone lets you, go to Settings -&gt; Accounts and sync and remove and re-add the account.