Paul's "charge" to young Timothy, just before the great apostle's martyrdom, was urgently needed by Christians in those early days of persecution and incipient apostasy, and his words are even more appropriate today.
The admonition to "be instant" is worth special note. The Greek word ephistemi is translated in various ways ("be present," "be at hand," "come upon," etc.). The main idea is simply to be there, doing what needs to be done at the time it is needed. In this particular context it is stressing the Christian's responsibility to be there with the right words from the Word of God--words of exhortation, of doctrine, of reproof if needed, yet words given patiently, even when rebuffed by the hearer. "Let your speech be always with grace, seasoned with salt, that ye may know how ye ought to answer every man" (Colossians 4:6).
Furthermore, the charge applies not only to those times when we are officially on duty, so to speak. It applies to off-hours as well as work time. Be instant out-of-season, as well as inseason! The Christian must always be "on call" when God calls.
The apostle could rightly issue such a charge because he himself had set such an example. "I have fought a good fight, I have finished my course, I have kept the faith: . . . thou hast fully known my doctrine, manner of life, purpose, faith, longsuffering, charity, patience" (2 Timothy 4:7; 3:10). It is touching that Paul could then use the same word (ephistemi) concerning his own coming death, when he said, "I am now ready to be offered, and the time of my departure is at hand" (2 Timothy 4:6). He was as ready to die as he had always been to speak, for the Lord! HMM