You have to keep updating Obsidian and all the themes and plugins you’re using for many reasons, including for security patches, bug fixes, and for accessing all the newer features the team has introduced.

Updating Obsidian:

1. Go to Settings → General → Check for updates.

Updating your theme:

1. Go to Settings → Appearance → Check for updates.
2. If there are available updates, click “Update all“.

Updating your plugins:

1. Go to Settings → Community Plugins → Check for updates.
2. If there are available updates, click “Update all“.

Be aware that, sometimes, a new Obsidian update may brake some some functions that third-party plugins and themes offer. You can always disable the problematic plugin or switch to another theme, report the issue to the developer, and wait until a patch is released.