Padre nostro, che sei nei cieli,noi
sia santificato il tuo nome,
venga il tuo regno, sia fatta la tua volontà,
come in cielo così in terra.
Dacci oggi il nostro pane quotidiano,
e rimetti a noi i nostri debiti
come noi li rimettiamo ai nostri debitori,
We've come across 'noi' before, with the first verb conjugation. I won't check, but I will have said that even though 'noi rimettiamo' means 'we remit', the 'noi' part meaning 'we', usually the 'noi' would be omitted.
In this case it isn't left out. Our forgiveness is dependent on the fact that we "forgive [our] brother from [our] heart", and consequently the 'noi' emphasises that we have to forgive before we can expect any forgiveness from God.
li
More pronouns for you:
lo, la, li, le
Those are some unstressed direct object pronouns. There are more, but these ones can be looked at together quite independently, so I will.
You remember I hope that direct objects are the ones directly affected by the verb? That is, in the following example, the word 'it' is the direct object.
He gave it to me.
'lo' and 'la' can both be translated as it, but 'lo' can also mean 'him', and 'la' can also mean 'her'. Of course, you use 'lo' where the pronoun stands for something masculine, and 'la' for something feminine.
More simply, 'li' and 'le' can both be translated as 'them', referring to both people and things. 'li' for masculine (in the plural), and 'le' for feminine (in the plural.
So 'li' means 'them'. 'li' here stands for the 'debiti' that we forgive our debtors.