Because Allah told him and his wife to eat from all the fruits in Jannah but to avoid just one tree. The Shaitan (Satan) whispered to him and convinced him that the tree would make them immortal. Adam disobeyed his Lord and tasted the fruit of the tree. So Allah Almighty expelled them from Paradise.
One sin cast Adam out of Paradise.
So what lesson do you learn from this? Is it logical for a person to with a sin no matter how small it is.
Allah has made all kinds of food Halal expect pork, and many people leave all kinds of permissible food and insist on eating pork (the one thing that Allah has made Haram (unlawful).,
Same with lawful relationships through marriage, many are those who go after unlawful relations.
Just as Allah made all drinks permissible except for alcohol and many are those who will insist on drinking alcohol.
“O Adam, dwell, you and your wife, in Paradise and eat therefrom in [ease and] abundance from wherever you will. But do not approach this tree, lest you be among the wrongdoers.” But Satan caused them to slip out of it and removed them from that [condition] in which they had been. And We said, “Go down, [all of you], as enemies to one another, and you will have upon the earth a place of settlement and provision for a time.”) [ Al-Baqara 2: 35-36]
(But Satan whispered to him, saying, “O Adam! Shall I show you the Tree of Immortality and a kingdom that does not fade away?”) Taha 20:120
لأنه عصى ربه إذ قال له الله تعالى أن يأكلا من كل ثمار االجنة إلا من شجرة واحدة. فوسوس الشيطان لآدم عليه السلام أنهما إذا أكلا من الشجرة الممنوعة ستجعلهما خالدين. فعصى آدم ربه و أكلا هو وزوجته من الشجرة.
معصية واحدة أخرجته من الجنة. ماذا تستفيد في حياتك العملية من ذلك؟ لا يعقل أن يستهين الإنسان بالمعاصي و لو قلت
أمثلة على ذلك:
أباح الله تعالى للإنسان أن يأكل كل شيئ إلا لحم الخنزير و بعض الناس يصرون على أكل لحم الخنزير.
و أباح الله تعالى كل أنواع المشروبات إلا الكحول فترى بعض الناس يتركون كل الحلال و يصرون على شرب الكحول
كما أحل الله الزواج فترى بعضهم يترك الحلال و يركض وراء العلاقات المحرمة
( ويَآءَادَمُ ٱسْكُنْ أَنتَ وَزَوْجُكَ ٱلْجَنَّةَ فَكُلاَ مِنْ حَيْثُ شِئْتُمَا وَلاَ تَقْرَبَا هَـٰذِهِ ٱلشَّجَرَةَ فَتَكُونَا مِنَ ٱلظَّالِمِين )
(وَقُلۡنَا يَـٰٓـَٔادَمُ ٱسۡكُنۡ أَنتَ وَزَوۡجُكَ ٱلۡجَنَّةَ وَكُلَا مِنۡهَا رَغَدًا حَيۡثُ شِئۡتُمَا وَلَا تَقۡرَبَا هَـٰذِهِ ٱلشَّجَرَةَ فَتَكُونَا مِنَ) ٱلظَّـٰلِمِينَ (٣٥) فَأَزَلَّهُمَا ٱلشَّيۡطَـٰنُ عَنۡہَا فَأَخۡرَجَهُمَا مِمَّا كَانَا فِيهِۖ وَقُلۡنَا ٱهۡبِطُواْ بَعۡضُكُمۡ لِبَعۡضٍ عَدُوٌّ۬ۖ وَلَكُمۡ فِى ٱلۡأَرۡضِ مُسۡتَقَرٌّ۬ وَمَتَـٰعٌ إِلَىٰ حِينٍ۬
البقرة 2 : 35-36
( فَوَسْوَسَ إِلَيْهِ ٱلشَّيْطَانُ قَالَ يٰآدَمُ هَلْ أَدُلُّكَ عَلَىٰ شَجَرَةِ ٱلْخُلْدِ وَمُلْكٍ لاَّ يَبْلَىٰ)
طه 20 : 120