The Greek verb prosecho (προσέχω) literally means to hold one's mind toward — to pay attention to, be on guard against, or devote oneself to something. It appears about 24 times in the NT.
Prosecho is the NT's warning verb. Paul warns Timothy: 'Watch your life and doctrine closely' (1 Timothy 4:16). Jesus warns: 'Watch out — be on your guard against the yeast of the Pharisees' (Matthew 16:6). Hebrews 2:1 makes the urgency theological: 'We must pay more careful attention, therefore, to what we have heard, so that we do not drift away.' The positive use: Acts 16:14 records that Lydia was paying attention as Paul spoke — prosechei is the threshold of conversion. Attention to the word is the first step of faith.