Trust in Allah and wazifas

The namaz and other wazifa which one reads does it have to be read will full concentration. Because the concentration does not always remain the same and infact it diverts to various places and things. One reads namaz because one has to read it as it if Fardh but it is not done with full concentration. One reads wazifa as one is idle and wants to be safe from satan or to accomplish certain thing like for job, marriage, etc. So one does it casually and does not take it seriously as he thinks that he is doing it atleast as on the road while walking or while sittle idle or lying down. Does one have to do it with full niyat and seriously or if not done with concentration it will not be fruitful.