Nothing Heavier on the Scale
The Prophet (sal Allahu alaihi wa sallam) said, “Nothing will be heavier on the Day of Resurrection in the Scale of the believer than good manners. Allah hates one who utters foul or coarse language.”
The most beneficial thing on the Day of Resurrection will be a courteous behavior which will outweigh all good actions. But that will be witnessed in case of a believer as there is no question of weighing a non-believer’s good actions. Allah Himself says in the Qur’an (interpretation of the meaning):
“So their works are in vain, and on the Day of Resurrection, We shall assign no weight for them.” [Al-Kahf 18:105]
And Allah knows best!