Authorship of Luke's Gospel

Why do we think Luke was the writter of the gospel?

1) Traditionally it is associated to Luke, and Luke with Paul. 

Come from 3 differenet traditional sources that we can rely on independantly: 

• 170-180 AD Luke mentioned as author, also as doctor who worked with Paul, wasnt a eye witness of events but was a " Follow of the Apostles" -  written in the MURATORIAN CANON. Gospel then seen as apostolic as he learned from apostles. 
• Notion of Luke as author held by early church fathers such as; IRANAUES, EUSEBIUS, ORIGIN, TERTULLIAN AND JEROME. Jerome was from Greece like Luke. Said gospel was written FOR GREEKS BY A GREEK. 
• ANTI-MARCIONITE PROLOGUE, states that Luke was a syrian of antioch (GREECE), a physician and a follower of PAUL/APOSTLES.  

These may not be seen as additional materail as stated in acts and apostle, may be viewed as unreliable source also. 

2) NEW TESTAMENT EVIDENCE 

a) writer of acts and gospel, implaceed WE passages, 27:1 " decided that WE should sale to Italy." And 28:16 "When we arrived in Rome." Both from act of apostles. 

Author speaks in first person, as if actually there. This suggests he was present with Paul and was therefore his companion on his journey. But this could have been written by anyone? Why say Luke wrote it? Some of followers of Paul are excluded such as Silas and Timothy who were both mentioned in Acts. 

b) HOBART, author has to be a doctor! 

Medical Knowledge shown i.e 

5:12 " Full of Leprosy" in later stages. 

4:38 " a great fever " 

speaks of also a surgical needle rather than a domestic one in parable of rich young man. This indicates some medical training. 

c) HAD compasion towards doctors unlike others such as MARK. 

example Mk 5:26 " Even though she had been treated by many doctors. She had spent all her money, but instead of getting better she got worse all the time. 

example Lk 8:43 " she…