Longtime best friend is agnostic but drawn to Islam. Emotionally supports me & urges me to worship Allah/seek closeness to Him. Given dawah & made dua for him for years. His character refined greatly, hates zina/alcohol but not Muslim yet. May I stay friends while giving dawah & what are the limits?

Ustadh AbdulAziz al-Haqqan

Choose wisely. If you see that this will help in making him enter into Islam, then keep dealing with him kindly and keep calling him to Islam. However, do not let this occupy your time, as your time is precious and you want to spend it in becoming a student of knowledge.