Let me answer you real quick. “Everything in the world is halal”. Yes, “Everything in the world is halal”. Only some of the things are haram (forbidden), yes, ONLY. And those that are haram (forbidden) in Islam because they are harmful for/to us.
Nouman Ali Khan said:
Allah has put many things in this world for us to use and consume and yet we remain thankless and show ingratitude. Good things are Halal and impure and filthy things are made Haram for us. The Halal things are actually a preview of sorts of what we shall attain in Jannah.
Halal is that which means permitted, allowed, lawful, or legal. Haram is that which is forbidden and unlawful.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
It should be understood that in principle all things, of various types and categories, are generally halaal for human beings, and that they are taahir (pure) and it is not forbidden for people to handle them and touch them. This is a comprehensive rule that is general in application, and it is an important ruling that is of immense benefit and brings much blessing, and the scholars turned to it when issuing ruling on innumerable actions and issues faced by people. It is based on by ten points of evidence – from what I can call to mind of sources of sharee‘ah – namely: the Book of Allah, the Sunnah of His Messenger, and following the path of the believers that is mentioned in the verses (interpretation of the meaning):
“Obey Allah and obey the Messenger (Muhammad (blessings and peace of Allah be upon him)), and those of you (Muslims) who are in authority”.-(Quran 4:59)
“Verily, your Walee (Protector or Helper) is Allah, His Messenger, and the believers”-(Quran 5:55);
in addition to qiyaas (analogy), consideration, rational thinking, and insight.
-Quote from Majmoo‘ al-Fataawa (21/535).