Since the new unit has: black/red/white/bare ground I assume even though the stove is gas the oven is electric.
If that is the case it operates from 120/240V, white is neutral, black and red are the hots.
The problem is grounding. Neutral and Safety ground need to be kept separate and only bonded together at the service disconnect. Stoves and dryers had a special exception for many years that is no longer in effect(except in grandfathered situations) that allowed safety ground to be bonded to neutral at the appliance.
I missed that you said the old wiring was black/white/ground. Since the old unit was all electric it must have used 120/240v. The only way to do that with a 3-wire cable is to re-purposed white as one of the hots and bare ground as Neutral. Before you mess with it need to check fuse or breaker cabinet to see is there is a single or two pole breaker (fuse) and exactly how it is wired.
I had assumed the unit came equipped with a plug, but whether it plugs in or is hard-wired the issue with neutral and ground is the same.
You really need to pull a new 3-wire/Wground cable rated for the current of the new unit.