New jar that you can't open? No need to buy special jar openers. The reason it's hard to open is that there is a vacuum inside the jar, so there is pressure difference between the inside and the outside. Equalise the pressure and it will open easily. All you need is a knife (like a dining knife), a flat-headed screwdriver or similar. Put the jar upside down on a flat, hard surface (e.g. a worktop, table or tray). Gently insert the knife or screwdriver between the jar and the lid. You may feel or hear a release of air, which is the pressure equalising. Then turn the jar the right way up and see if you can open it. Try again if it doesn't work first time.