You cultivate all positive qualities when you make the Hereafter your goal. When you make worldly gain your goal, you will become selfish, adopt cheap ways, speak lies and show base character.
The Quran says: You love immediate gain and neglect the Hereafter. (75:20-21) People are trapped in material gain, whether achieved honestly or by speaking lies. People have forgotten about the gain of the Hereafter. This makes a person truthful. It develops noble character. You cultivate all positive qualities when you make the Hereafter your goal. When you make worldly gain your goal, you will become selfish, adopt cheap ways, speak lies and show base character.
These negative traits will develop in one who makes the world his goal. If a person makes the eternal Hereafter his goal, he will develop positive qualities. This is what I have understood.