1 Corinthians 16:10 (ESV)

10 When Timothy comes, see that you put him at ease among you, for he is doing the work of the Lord, as I am.

Earlier in his letter (1 Corinthians 4:17) Paul told the Corinthians that he is sending Timothy to them, so that Timothy can remind them of the things that he (Paul) has taught them. In the same passage (1 Corinthians 4:18) he referred to arrogant people in the Corinthian church. It is probably on account of these people that Paul now urges the Corinthians to make sure that Timothy will be at ease (literally: without fear) among them.

Timothy was still a young preacher and likely prone to fearfulness (1 Timothy 4:12; 2 Timothy 1:6–7). Yet the Corinthians must welcome him because of the work that he is doing. With the words as I am, Paul places Timothy on equal footing with himself. They are both serving the Lord as preachers and teachers (see 1 Timothy 5:17).