So I was trying to translate the lyrics from the 1st OP of Getter Robo Armageddon anime into my language and right now I'm stuck with this "信じる心に". It would be very much appreciated if someone could give me an explanation of it.
The full line is:
and the English translation I have looked up is
If you need to fight for your beliefs and for the future
but I don't quite understand.
Full verse for context: