Apostle, Apostleship - Vine's Expository Dictionary of New Testament Words
Apostle, Apostleship[ 1,,G652, apostolos ]
is, lit., one sent forth" (apo, "from," stello, "to send"). "The word is used of the Lord Jesus to describe His relation to God, Hebrews 3:1; See John 17:3. The twelve disciples chosen by the Lord for special training were so called, Luke 6:13; Luke 9:10. Paul, though he had seen the Lord Jesus, 1 Corinthians 9:1; 1 Corinthians 15:8, had not 'companied with' the Twelve 'all the time' of His earthly ministry, and hence was not eligible for a place among them, according to Peter's description of the necessary qualifications, Acts 1:22. Paul was commissioned directly, by the Lord Himself, after His Ascension, to carry the Gospel to the Gentiles.
"The word has also a wider reference. In Acts 14:4, Acts 14:14, it is used of Barnabas as well as of Paul; in Romans 16:7 of Andronicus and Junias. In 2 Corinthians 8:23 (RV, margin) two unnamed brethren are called 'apostles of the churches;' in Philippians 2:25 (RV, margin) Epaphroditus is referred to as 'your apostle.' It is used in 1 Thessalonians 2:6 of Paul, Silas and Timothy, to define their relation to Christ." * [* From Notes on Thessalonians, by Hogg and Vine, pp. 59-60.]
[ 2,,G651, apostole ]
"a sending, a mission," signifies an apostleship, Acts 1:25; Romans 1:5; 1 Corinthians 9:2; Galatians 2:8.
Note: Pseudapostoloi, "false apostles," occurs in 2 Corinthians 11:13.