Hazrat Muhammad (SAW) once said: Let me tell you of the gates of virtue (they are):
1) fasting which is an armour against hell.
2) giving charity (As-Sadaqah) which erases sins just like water extinguishes fire.
3) worshiping and remembering Allah in the middle or (the last third) part of the night.
Abu Dawud and At-Trimzi (Tafsir Al-Qurtubi)