1994 Lincoln Continental Stop Get Gas Turned Car Off Put Turn Back On Now

Check the transmission fluid level and condition if okay have the transmission further checked for slippage by a transmission shop.

I will take it that you have not read your owners manual...

This is a problem with the Shift Interlock System and not the transmission
it is called a intermittent transaxle lock,

to by pass the shift-lock,
b4 starting vehicle,
place key into the "RUN" position,
slide shifter down into neutral (note for dummys, make sure ur holding break down!)
start car and move to desired shift position.

whats causing this?
There are a couple of possibilities.
The first is the Brake Pedal Position (BPP) switch.
You can usually tell if this is bad if you have no brake lights at all.
Another possibility is a bad Shift Lock Actuator or Shift lock solenoid,
located under the console.