Cranks but wont start

I have had no problems with my car until yesterday. I went out to start it and nothing happened. All the dash lights, radio, windows, everything works except the car won't turn over. There is nothing when I go to turn the key in the start position. I have checked the battery connections, fuses, there is a full tank of gas in it also. You can hear the fuel injector open too. The only way that I can get it to crank is by putting a screwdriver on the starter but it still won't fully start. I have had no problems before this, the car ran fine and hasn't given me any reason for concern. I had someone mention the neutral safety switch but I don't know where to look to find it. If someone can help it would be greatly appreciated!