After being discharged, a debtor begins making payments on a debt that was listed in the bankruptcy.

He does this for five years, paying back about a third of the debt, then stops.

Does the debtor's repayment history somehow revive the debt and thus allow the creditor to successfully sue for the balance or will the debtor be able to hide behind the original bankruptcy.

This takes place in Canada.

No the debt is not revived. The payments were nothing more than a gift unless you sign an affirmation agreement containing new consideration.