The word “apostolic” means different things to different people. In general it refers to the doctrines and practices of the original apostles. Some people make a distinction between “pentecostal” and “apostolic.” Anyone who has received the experience of Pentecost (speaking in tongues as the Spirit gives utterance) may be called Pentecostal. But only those who obey the plan of salvation stated by Peter on Pentecost (Acts 2:38) are called Apostolic. In other words, all Apostolics are Pentecostal, but not all Pentecostals are Apostolic. In this sense, the word “apostolic” applies primarily to the plan of salvation preached by the Apostles. Most Apostolics also believe in the Oneness of God and holiness of life.
The word “apostle” means “one who is sent out.” Since we are all divinely sent out to preach the gospel and show the character of God, in the broadest sense “apostolic” refers to the mission of all true believers to receive from God and manifest what they have received to the world. We are all apostolic, though some do not realize it.