need a bridge?

[Jhonny Boy]

Hello
I would like to creat a AP to share my internet connection. I followed a gentoo documentation.
But I wonder do I need to creat a bridge?
Can't I forward my connection with iptable in order to filter it?

I configure /et/hostap/hostap.conf and when I try to launch it I have this mistake :
 * Starting wlan0
 *   Configuring wireless network for wlan0
 *     no access points found
 *   Couldn't find any access points on wlan0
 *   Failed to configure wireless for wlan0                      [ !! ]
 * ERROR:  cannot start hostapd as net.wlan0 could not start

Is it beceause I didn't activate the bridge?