Real happiness and peace can be found in submitting to the commands of the Creator and the Sustainer of this world. God has said in the Quran:
“Truly, in remembering God do hearts find rest.” (Quran 13:28)
On the other hand, the one who turns away from the Quran will have a life of hardship in this world. God has said:
“But whoever turns away from the Quran, he will have a hard life, and We will raise him up blind on the Day of Judgment.” (Quran 20:124)
This may explain why some people commit suicide while they enjoy the material comfort money can buy. For example, look at Cat Stevens (now Yusuf Islam), formerly a famous pop singer who used to earn sometimes more than $150,000 a night. After he converted to Islam, he found true happiness and peace, which he had not found in material success.
 i.e. neither believes in the Quran nor acts on its orders.
 The present mailing address of Cat Stevens (Yusuf Islam), in case you would like to ask him about his feelings after he converted to Islam, is: 2 Digswell Street, London N7 8JX, United Kingdom.