I don't really know enough about your case facts to tell you what you could say to oppose a lift of the automatic stay.
I also don't know which bankruptcy court you are in, but if it's the Central District, then you can start with this form.
Note: If your position is that the property is not part of the bankruptcy estate, because it was transferred to someone else, then be aware, that if a trust deed was recorded with the county, prior to the date when your parents conveyed a deed to a new owner, and the loan secured by the trust deed was not paid off first, then that trust deed has priority and your parents transfer would have no legal effect on the lender's right to foreclose the loan. Which means that you would lose your motion. Though, you may be able to get the court to postpone the sale for a bit longer.
Hope this helps.
Terms and Conditions: By your continuing in this conversation with me, or by your clicking “Accept”, you are expressly agreeing to all of the following: (1) our communication is for entertainment purposes only; (2) you are not consulting me in my professional capacity as an attorney; (3) you do not seek to establish an attorney-client relationship with me, nor do I with you; (4) you will not rely on anything I say and you will obtain appropriate legal counsel via a traditional/office consultation with an attorney licensed to practice in the jurisdiction where your legal issue arises (and you may not use our communication to avoid taxpayer penalties imposed by the U.S. Dept. of Treasury); (5) by communicating with me in this public forum you are irrevocably waiving any right to privacy, confidentiality and attorney-client privilege concerning the matters discussed. You further separately declare that any payment made by you is not consideration for this contract, nor offered for any services rendered by me on your behalf, but rather is made in genuine admiration and respect for my desire to help others. If you do not agree with these terms and conditions, then you must advise me immediately.