"However, I consider my life worth nothing to me, if only I may finish the race and complete the task the Lord Jesus has given me - the task of testifying to the gospel of God's grace." NIV translation
Paul is willing to die in his efforts to share the gospel. He is focused on the task at hand and convinced that, even if he dies, he will be better off with Jesus. That may seem like radical faith to us but, if you think about it, why should we fear going to be with the Lord? Fear is not from God it is a tool that the devil uses to get us to take our focus off of the task at hand which is sharing the gospel. Paul knew that and we can too!
Paul tells the Ephesian elders that he knows that they will not ever see him again.He then goes on to explain how he is innocent of the blood of men because he shared the gospel. This is from Ezekiel 3:17-19 where God talks about being a watchman for the people.
We must understand that God has made all of us who are Christians to be watchmen for the world. If we do not share the gospel with the people we come into contact with, we can be guilty of their blood if they die without Christ.
"Keep watch over yourselves and all the flock of which the Holy Spirit has made you overseers. Be shepherds of the church of God, which he bought with his own blood." NIV translation
Paul urges the elders to not only watch over the believers but also to watch over themselves as he knows that there will be attacks. He reminds them to be shepherds and that the "church" was bought at a heavy price. A shepherd's main job is to protect the flock and so Paul urges them to be watchful.
"'I know that after I leave, savage wolves will come in among you and will not spare the flock. Even from your own number men will arise and distort the truth in order to draw away disciples after them. So be on your guard! Remember that for three years I never stopped warning each of you night and day with tears.'" NIV translation
Now, Paul warns them of the dangers that face them and the worst of all is distorting the gospel. Paul even warns the Ephesian elders that, some from their own number, will distort the Word of God to get people to follow them. It seems that Paul could be talking about many people today as it seems that "churches" are in a competition to be the biggest or have the most programs. Many today are seeking numbers instead of the lost and distorting the Word to draw people in instead of proclaiming the Word to lead people to salvation. This is just what Paul was warning them (and us) about.