﴿ لَّقَدْ سَمِعَ ٱللَّهُ قَوْلَ ٱلَّذِينَ قَالُوٓا۟ إِنَّ ٱللَّهَ فَقِيرٌۭ وَنَحْنُ أَغْنِيَآءُ ۘ سَنَكْتُبُ مَا قَالُوا۟ وَقَتْلَهُمُ ٱلْأَنۢبِيَآءَ بِغَيْرِ حَقٍّۢ وَنَقُولُ ذُوقُوا۟ عَذَابَ ٱلْحَرِيقِ ﴾

“God has indeed heard the saying of those who said, "Behold, God is poor while we are rich!" We shall record what they have said, as well as their slaying of prophets against all right, and We shall say [unto them on Judgment Day]: "Taste suffering through fire”

One comes to be called a believer by just repeating some words (kalimah), but so far as God is concerned, the would-be Muslim becomes a believer only when he sacrifices his life and his wealth for His cause. Without such a sacrifice, nobody’s faith is credible in the eyes of God. One thinks that by safeguarding one’s money one is safeguarding one’s worldly future. But man’s real future is that which pertains to the Hereafter. And money amassed for worldly purposes will only prove to be a curse for the hoarder.