Sayyiduna Shaddad bin Aws (may Allah be pleased with him) says that the sermon of the Messenger of Allah (peace and blessings be upon him) was this: "The world is a present commodity; the righteous and the wicked eat from it. And the Hereafter is a true promise in which a King possessing power will judge. Beware! All good, in its entirety, is in Paradise, and beware! All evil, in its entirety, is in Hell. So act, and fear Allah. Know that your deeds will be presented to you, and that you will certainly meet your Lord." [Surah al-Zalzalah: 7-8]
"So whoever does an atom's weight of good will see it, and whoever does an atom's weight of evil will see it as well."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5808