It is strongly recommended that you do have a Will as there are many important benefits to be gained.
If you die intestate, your estate will be divided amongst your family members in accordance with the Intestacy Rules. Of course, this may not be how you would prefer your Estate to be divided.
However in the absence of Will, your wishes are irrelevant.
Whilst dividing your estate in accordance with the Intestacy Rules may not seem terrible, not all of your loved ones will be entitled to receive a share of your Estate. Step-children will not receive anything under the rules from the Estate unless the deceased had formally adopted the step-child. They would need to make an application to court to try to receive a share of the Estate.
In your Will, you can choose who will take a share of your Estate and how much. You can also specify whether you would like to be buried or cremated, nominate a guardian to care for any of your children who are under 18 years of age and state that you wish to donate body organs.