Is it safe to use a soft 3 way 30/50/150 Watt incandescent bulb in a lamp that requires 23 CFL max light to prevent fire. It is the only bulb that I could find but only the 150W setting works with this bulb in the lamp. I want the bright light so am hoping this light will be safe to use. The volts are 120 for this light.
No, that is not safe. The 23W CFL limit means that you should not use a bulb that uses more than 23W of power. A 30/50/150W 3-way will use more than that on its lowest setting.
If you don't want to use a CFL, and I don't blame you, please consider an LED bulb. These generate even less heat than a CFL. Use the ACTUAL power rating, which is likely to be in the 5-10W range rather than the "equivalent" power rating.
First, this is dangerous as discussed by everyone else. "convenience" is not an exception to
Second, a 50/100/150 incandescent will NOT give you 150W in that fixture. It will only give 100W, because of the way the bulbs are internally wired.
However, there are "50/100/150" LED bulbs that are actually in the 23W neighborhood. And even better, they do an internal trick so you get the maximum brightness "150" in a simpler fixture like yours. That's what you actually want.
That said, these LED bulbs do cost some money, but you only have to buy them once.