How to overcome spiritual attacks

In my journey as a Christian l have found that many Christians around the world are suffering with many challenges in their marriages, family, finance, business and job and sometimes they wonder if God really exist. They cry to God day and night for there is terror everywhere and their lives are miserable. They go from prophet to prophet, church to church and to some extent country to country seeking for an answer but nothing seem to be working. Some of them they have reached the level of not believing the man of God because a miracle that have been prophesied upon their lives but nothing happened and they have been waiting for years for that marriage, business, children, car but nothing seems to be coming. Their lives are just in circles, hundred percent efforts but no result, they do rather have no hope than hoping for nothing. Today l have good news for you; don’t pack your bags yet because God is still saying something. Joel 2; 25 say