If you allow the cream cheese to come to room temperature first, you could use what cooks used before there were blenders: a mechanical egg beater, the kind you crank around and around. It will just take a bit of work is all.

But, Mr. Novice Cook, you really need to get a blender. Every kitchen should have one, IMO. Every. Kitchen. And they are cheap! Even cheaper if you buy one at a garage sale.

A small food processor is also cheap, but does not hold the volume that a blender can.

If you can afford it, I recommend the Vitamix blender. It is so versatile and well made. I've used it to make nut butters, chop onions, make smoothies, cream of vegetable soups, and so much more. I've had mine over 20 years and expect it to last indefinitely. Plus, what other company can you name that gives their merchandise a 7 year warranty?!

Vitamix

(No, I do not work for the company.)