According to the Bible an apostle is an ambassador of the gospel with miraculous powers. Apostles are commissioned by God to speak and to act under, and with His authority.
The apostles must be in the will of God to be able to 'go ye into all the world and preach the Gospel to every creature'. The apostles were the leadership throughout the New Testament and they must maintain that quality today. Their teachings must be verified by the Word. The Lord will come to them and call them unto Himself.
Weakened churches say the apostolic age died with the original Twelve. UNTRUE! What about Paul? To say such a thing makes God's word void! Peter spoke in Acts 2:38-39, "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and your children, and to all that are afar off, even as many as the Lord our God shall call." Until God stops calling, the apostolic message and power will not cease! There are many pseudo-apostles today. God warned of them - 'For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; Whose end shall be according to their works.' ~2 Corinthians 11:13-15
Apostles must be blameless. They should possess the power of Peter, have the grace of John and the insight of Paul. And above all else, they should be like Jesus Christ.