Will not start?

I have replaced the alternator, the battery, plugs, plug wires, you name it. It tries its hardest to start, it turns over. It has gas going to it it has spark but it will not start. I'm at my witts end. I absolutely love this car it's about and paid for so I don't want to have to buy a new one I just can't get it to start. I'm to the point I'm ready to burn it to the ground. I replaced sensor after sensor and I just cannot afford to keep playing the guessing game. I can't get anybody to help me any suggestions out there.