How should Muslims who do not fast Ramadan be treated, and what are the best ways to invite them to fast?

Muslims should be invited to fast and encouraged to do so, while being warned against negligence, through several means: informing them of the obligation of fasting and its stature, and reminding them of the great reward associated with it, as stated in the noble hadiths: "Whoever fasts Ramadan out of faith and hope for reward, his past sins will be forgiven," and "Whoever believes in Allah and His Messenger, establishes prayer, and fasts Ramadan, it is a right upon Allah to admit him into Paradise," and "Fasting is for Me, and I shall reward for it." They should also be warned against abandoning fasting, clarifying that it is one of the major sins, as mentioned in the hadith about those suspended by their ankles for breaking their fast before its permissible time. Furthermore, the ease and simplicity of fasting should be clarified, along with the joy and happiness it brings. They should be encouraged to attend lectures and read pamphlets about fasting, and one should not tire of inviting them with gentle words and supplicating for their guidance.