We have a very great responsibility to demonstrate to the next generation what Christlikeness really means. People who look at us - the way we live, preach and serve - should be able to see in us what it means to be a true servant of the Lord, in the style of the apostles and prophets of old, and not in the style of 20th-century film-star-like evangelists.
Whether we realise it or not, we're leaving behind us an image, wherever we go - an image that's going to remain in people's minds long after we've gone away and long after they have forgotten the messages that we preached to them.
When Paul called the elders of the church in Ephesus to bid farewell to them, notice what he told them in Acts 20:17-35. He reminded them that he had been with them for three years (verse 31) and that he had preached to them night and day. Three years is more than 1000 days. And so if Paul actually preached twice every day, as it seems to imply here, he must have preached over 2000 sermons there.
Ephesus was the place where they had once had a great revival and where Christians had burnt their old books of magic and witchcraft costing nearly half a million rupees. It was also the place where handkerchiefs that had touched Paul's body were used to heal the sick and deliver the demon-possessed. God did some amazing miracles through Paul in Ephesus on a scale that hadn't been seen anywhere else (See Acts 19:11,12,19).
At the end of all this, what does Paul remind the elders of? Does he remind them of his sermons or the miracles? No. He tells them to remember the humble way he had lived among them, from the first day they had seen him (v.19). Even if they forgot his sermons, they could never forget how he lived among them. His life had made a permanent impact on them. They could never forget his compassion and his simplicity. They'd remember that he had worked hard with his own hands as a tentmaker to support himself and his coworkers - so that he would not be a burden to them and also to be an example to other Christian workers (v.34,35). They would never forget that during all those three years, Paul never desired money, or gifts, or even a new set of clothes, from any of them (verse 33)!
Paul also reminded them how he had proclaimed the WHOLE counsel of God to them uncompromisingly (Acts 20:27). He hadn't been a man-pleaser, seeking popularity for himself. He had preached repentance and every other unpopular subject, if it was profitable for his hearers, even if some got offended thereby (Acts 20:20, 21).