(Lukman) 31 : 4
الَّذِينَ يُقِيمُونَ الصَّلَاةَ وَيُؤْتُونَ الزَّكَاةَ وَهُمْ بِالْآخِرَةِ هُمْ يُوقِنُونَ
Those who are keeping up prayer and are giving welfare tax, and they are having confirmed belief with the Hereafter.
See explanation 2: 3-4; 7: 205-206, and 8: 2-4