How to reformat a iPhone 4 (Verizon) without apple password?

My dad gave me his iPhone 4 and I want to format it but my dad forgot his Apple ID. Is there anyway I can format it without using the iPhone password? (BTW I'm from the PH and there's no Verizon here, my dad bought it from the US)

Fail the password on the phone multiple times and it wipes automatically.

No. Although too many failed password attempts will wipe the phone, you still can't use it with your Apple account unless your dad unlocks it.

He doesn't need to remember his password as Apple make sure that users set up a password resetting service for those occasions where people forget. He just needs access to whichever email addresses he used when he set up the phone. If he's forgotten that as well then the phone is useless as you can't bypass the security.

If he forgot the password then he should check about resetting it & then you could go about resetting it. Can't do it otherwise.