It is not wrong to want to live better; what is wrong is a style of life which is presumed to be better when it is directed towards 'having' rather than 'being,' and which wants to have more, not in order to be more but in order to spend life in enjoyment as an end in itself.
Pope John Paul IThe priestly vocation is essentially a call to sanctity, in the form that derives from the Sacrament of Holy Orders. Sanctity is intimacy with God; it is the imitation of Christ, poor, chaste and humble; it is unreserved love for souls and self-giving to their true good; it is love for the church which is holy and wants us to be holy, because such is the mission that Christ has entrusted to it. Each one of you must be holy also in order to help your brothers pursue their vocation to sanctity.
Pope John Paul I