In the first sentence, besides "my father," you also need to add the article "a" before "good person":

Correct: I accept my father's orders because I know that my father wants me to be a good person.

It's also fine to use a pronoun instead of repeating "my father" in the sentence a second time:

I accept my father's orders because I know he wants me to be a good person.

Edit: Sorry, I meant to say "The third sentence.........."

First two are fine except for a spelling mistake in the first sentence: ......My father.

The sentence is very unnatural. Better:

She accepted this job only because she needs the money.

Please, if everything is correct, just leave comment to help me to know that, thanks .

I accept my father's orders because I know that mu father wants me to be good person .

( Verb : Accept - Tense : Present simple ) .

The university is accepting new students until the end of this month .

( Verb : Accept - Tense : Present continuous ) .

She accepted to work this job, only because she needs money .

( Verb : Accept - Tense : Past simple ) .