N.J. Stat. Ann. § 2A:50-44

The judgment entered in a foreclosure proceeding under authority of section 2A:50-43 of this title shall be only for the amount of the principal which would have been due as of the date of the filing of the complaint to foreclose, had there been no default, together with all interest accrued as of the date of the judgment, and costs, and shall adjudge that the mortgage shall not be deemed to have merged in the judgment, but shall remain in full force and effect as security for the principal sum remaining due thereon, after deducting the principal sum to be paid because of such default, and interest upon such principal sum to become due thereon from the date of the judgment.