Why did the address "O Children of Adam" appear in the noble verse "Take your adornment at every Masjid," instead of an address to the believers, and do all people go to Masjids, or is it only the believers who go to them?

The verse (O Children of Adam) was revealed to address all people, believers and disbelievers alike, because it was intended for those Arabs who used to circumambulate the Kaaba naked. It is general for every mosque for prayer, as the rule is based on the generality of the wording, not the specificity of the reason. Women used to circumambulate the Kaaba naked, placing a small piece of cloth over their private parts, and saying: "Today, part or all of it will appear, and what appears of it I do not permit." So, the verse was revealed.