We are purchasing a home through owner finance. the Contract written says after 90 days late making the payment the seller can take possession of the

You don't provide much detail.  You don't indicate whether this is just a casual inquiry about something in the contract, or whether you have defaulted for over 90 days and now find yourself losing the property. Let me just say that contracts are designed to "bind the parties" to the particular agreements contained in the document.  If the contract says you must not get behind with a payment more than 90 days or you will lose the property -- that is exactly what it means.  If you signed a contract bearing those terms, then you promised that you would live up to it or you would agree the property would be lost.  If there is any way to recover the fumble, it must be through another agreement.  See a good real estate lawyer in your area.