At the start of Peter's second and last letter, he described himself as a servant and apostle of Jesus Christ.  Once, he had been a disappointment to Jesus (Matthew 26:69-75).  But, when restored, he had been 'sent out' (that is what 'apostle' means) by Jesus to preach the gospel (John 21:15-19).  God worked through his ministry (Galatians 2:8), even though he still needed to learn (Galatians 2:11-13).  Now, at the end of his life, he was still glad to be trusted as Christ's servant.

The apostles all met the risen Lord Jesus Christ (including Paul on the Road to Damascus).  Their job was to announce to the world all that Jesus had done and taught (Matthew 28:18-20) (Acts 1:1-8).  Peter was one of the three closest disciples to Jesus, with the fisherman brothers John and James.  Peter had closely witnessed the raising of Jairus’ daughter (Mark 5:37-43), the transfiguration (Mark 9:2) (2 Peter 1:16-18), Christ's agony in Gethsemane (Mark 14:32-34), the empty tomb (John 20:3-7) and met the risen Jesus (John 21:1-7).  Peter was one of the three leaders of the church in Jerusalem with fellow apostles James and John (Galatians 2:9), but was finally based in Rome (1 Peter 5:13).  What a set of amazing experiences, but he presents himself a servant of Jesus Christ.  
 
Although the Bible honours the apostles, Peter was quite clear that his faith was essentially no different from that of every true believer in Jesus.  He and the Apostle Paul (1 Corinthians 15:9) knew that they did not deserve to be in favour with God.  It was only through God's sovereign grace that they had been given the ability to trust and to keep trusting - just like every other believer.  Peter's place in God's family was not due to his special holiness, but to the extra special righteousness of God.  Peter's salvation, and ours, was secured as God the Father and God the Son worked together: the Father accepted the sufferings of Jesus as a full, complete and perfect atonement for the sins of all who would believe (1 Timothy 1:16).

To be able to believe that is very precious (1 Peter 2:7) - because it was so costly to Jesus to make us right with God.  Peter was personally grateful to Jesus and wanted others to know too.  He accepted the apostolic role but knew that neither his ministry nor his title could make him holy; only Jesus could do that by His personal sacrifice (see www.crosscheck.org.uk to know more).  And however high a pedestal some might put Peter on, he knew that he was just a servant of Jesus Christ.  The same is true for all of us.  Whatever our calling, position or ministry, we remain servants of Jesus.  It is His right to command and direct; it is our privilege to submit and obey.  There is no higher calling.