The verses below are the words Paul gives to his son in the faith, Timothy. He urges him to carry out his calling without spot or blemish. I don't think Paul is saying that Timothy has to be perfect in his behavior as much as being faithful to his calling. And as he pursues this calling, he is to keep in mind that Jesus will appear again in great and promised glory. Importantly though, we don't know when this time will come, only God does.
Jesus was faithful in his calling to His Father, even when his life was on the line with his trial before Pontius Pilate. Jesus remained faithful even unto death on the cross. Paul would soon himself carry out his calling to his own death. Eusebius, church historian, says that Timothy became the bishop of the church at Ephesus, where Paul left him in charge. Tradition says this about Timothy's death,
"The apocryphal Acts of Timothy states that in the year 97, the 80 year old bishop tried to halt a procession in honor of the goddess Diana by preaching the gospel. The angry pagans beat him, dragged him through the streets, and stoned him to death."
It appears that young Timothy was faithful to the charge his mentor Paul gave to him, even unto death. Timothy's success is not so much being perfect as fighting the good fight of faith with the strength and power Jesus gave him.
While we are not all going to become bishops, we are all called to be faithful to the charge we are given as Jesus' disciples. In God's time Jesus will appear, and our goal, like Timothy's faithful to whatever and wherever our own call leads us to in His strength and power.
1 Timothy 6:13-16
13 In the sight of God, who gives life to everything, and of Christ Jesus, who while testifying before Pontius Pilate made the good confession, I charge you 14 to keep this command without spot or blame until the appearing of our Lord Jesus Christ, 15 which God will bring about in his own time—God, the blessed and only Ruler, the King of kings and Lord of lords, 16 who alone is immortal and who lives in unapproachable light, whom no one has seen or can see. To him be honor and might forever. Amen.