Was Paul really an apostle?

Q. Paul wrote that he as an apostle not of men neither by man. Had he Ananias or Barnabas in mind when he wrote 'by man'?

A. In each introduction where Paul wrote he was an apostle (Greek: ἀπόστολος , Strong's Concordance Number #G652, meaning 'one who is sent, ' a messenger), he attributes his calling to God or Jesus Christ or both (Romans 1:1; 1Corinthians 1:1; 2Corinthians 1:1; Galatians 1:1; Ephesians 1:1; Colossians 1:1; 1Timothy 1:1; 2Timothy 1:1). Only in Galatians does he insert the parenthetical statement:

"Paul, an apostle, (not of men, neither by man, but by Jesus Christ, and God the Father, who raised him from the dead;)" (Galatians 1:1, KJV)

According to Robertson's Word Pictures In The New Testament,

"The bluntness of Paul's denial is due to the charge made by the Judaizers that Paul was not a genuine apostle because [he was] not one of the twelve."

B W Johnson, author of The People's New Testament states,

"...this Epistle [Galatians] was written on account of the disturbance made among the churches of Galatia by false teachers. These teachers sought to prepare a way for their doctrines by discrediting Paul. If they admitted that he was an apostle at all, they claimed that he was inferior to Peter and the Twelve; that he had received his gospel from them, and hence all must look to Jerusalem for the true gospel. "

Dr John Gill in his Exposition Of The Whole Bible states,

"[Paul] asserts himself to be an apostle, which was the highest office in the church, to which he was immediately called by Christ, and confirmed in it by signs and wonders. This he chose to mention, because of the false teachers, who had insinuated he was no apostle, and not to be regarded...."

Dr Gill continues,

"...what Ananias did upon his [Paul's] conversion was only putting his hands on him to recover his sight, and baptizing him; it was Christ that appeared to him personally, and made him a minister; and his separation with Barnabas, by the church, under the direction of the Holy Ghost (Acts 13:2), was to some particular work and service to be done by them, and not to apostleship, and which was long after Paul was made an apostle by Christ."