Paying the rent is one of your most important obligations as a tenant. So you must always pay the rent. You cannot decide to stop paying the rent yourself.
Are you no longer able to pay the rent? Contact the OCMW in your municipality.
What if you do not pay the rent? Then the landlord can start a legal procedure with the justice of the peace to ask for the rent arrears. Is there persistent rent arrears (2 months or more)? Then the landlord can ask the justice of the peace to terminate the rental contract and evict you from the property.
Does the justice of the peace decide to stop the lease? Then you must vacate the property on short notice. If you don't, a bailiff can physically evict you. In addition, you will have to pay the overdue rent to the landlord as well as the costs of the legal proceedings and/or the bailiff. Try to avoid this.
Important: the landlord can never evict you him/herself. This is only possible after a decision by the justice of the peace.