Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
quran:4:74

So let those fight in the cause of Allah who sell the life of this world for the Hereafter. And he who fights in the cause of Allah and is killed or achieves victory - We will bestow upon him a great reward.  

God, exalted be He, says: So let them fight in the way of God, to elevate His religion, those who sell the life of this world for the Hereafter; and whoever fights in the way of God and is slain, dies a martyr, or conquers, overcomes his enemy, We shall give him a great wage, a plentiful reward.
القرآن:٤:٧٤

فَلْيُقَاتِلْ فِي سَبِيلِ اللَّهِ الَّذِينَ يَشْرُونَ الْحَيَاةَ الدُّنْيَا بِالْآخِرَةِ ۚ وَمَنْ يُقَاتِلْ فِي سَبِيلِ اللَّهِ فَيُقْتَلْ أَوْ يَغْلِبْ فَسَوْفَ نُؤْتِيهِ أَجْرًا عَظِيمًا  

{فليقاتل في سبيل الله} لإعلاء دينه {الذين يشرون} يبيعون {الحياة الدنيا بالآخرة ومن يقاتل في سبيل الله فيُقتل} يستشهد {أو يَغلب} يظفر بعدوه {فسوف نؤتيه أجرا عظيما} ثوابا جزيلا.