The first part of the second question 62 By the first part of its second question , the referring court essentially asks whether , under EU law , a national court is required , in a dispute between individuals , to disapply a provision of national law that cannot be interpreted in a manner that is consistent with the second subparagraph of Article 4 ( 2 ) of Directive 2000 / 78 . 63 It must be recalled that it is for the national courts , taking into account the whole body of rules of national law and applying methods of interpretation recognised by that law , to decide whether , and to what extent , a national provision , such as Paragraph 9 ( 2 ) of the AGG , can be interpreted in a manner that is consistent with Article 4 ( 2 ) of Directive 2000 / 78 , without having recourse to an interpretation contra legem of the national provision ( see , to that effect , judgment of 17 April 2018 , Egenberger , C ‑ 414 / 16 , EU : C : 2018 : 257 , paragraph 71 and the case-law cited ) . 64 The Court has held , moreover , that the requirement to interpret national law in a manner that is consistent with EU law includes the obligation for national courts to change their established case-law , where necessary , if it is based on an interpretation of national law that is incompatible with the objectives of a directive ( judgment of 17 April 2018 , Egenberger , C ‑ 414 / 16 , EU : C : 2018 : 257 , paragraph 72 and the case-law cited ) . 65 Consequently , a national court cannot validly claim that it is impossible for it to interpret a provision of national law in a manner that is consistent with EU law merely because that provision has consistently been interpreted in a manner that is incompatible with EU law ( judgment of 17 April 2018 , Egenberger , C ‑ 414 / 16 , EU : C : 2018 : 257 , paragraph 73 and the case-law cited ) . 66 In the present case , therefore , it is for the referring court to ascertain whether the national provision at issue in the main proceedings lends itself to an interpretation that is consistent with Directive 2000 / 78 . 67 In the event that it is impossible to interpret the national provision at issue in the main proceedings in a manner that is consistent with EU law , it should be noted , first , that Directive 2000 / 78 does not itself establish the principle of equal treatment in the field of employment and occupation , which originates in various international instruments and constitutional traditions common to the Member States , but has the sole purpose of laying down , in that field , a general framework for combating discrimination on various grounds , including religion and belief , as may be seen from its title and from Article 1 ( judgment of 17 April 2018 , Egenberger , C ‑ 414 / 16 , EU : C : 2018 : 257 , paragraph 75 and the case-law cited ) . 68 On the other hand , a national court that finds itself in the situation referred to in the paragraph above is under an obligation to provide , within the limits of its jurisdiction , the legal protection which individuals derive from EU law and to ensure the full effectiveness of that law , disapplying if need be any provision of national legislation contrary to the principle prohibiting discrimination on grounds of religion or belief ( see , with regard to the principle prohibiting discrimination on grounds of age , judgment of 19 April 2016 , DI , C ‑ 441 / 14 , EU : C : 2016 : 278 , paragraph 35 ) . 69 Before the entry into force of the Treaty of Lisbon , which conferred on the Charter the same legal status as the treaties , that principle derived from the common constitutional traditions of the Member States .