This is the "Great Commission", the last thing Jesus said before ascending into heaven. It has inspired and motivated Christians for 2000 years and more. It's the reason he hasn't taken us to heaven with him yet - there's a job to be done here first, and he's entrusted it to us!
Here's some advice that Paul gave to Timothy about "fighting the good fight". It contrasts the way some people live, with the life a real Christian soldier ought to be living if he/she wants to wage war successfully against the enemy.
Here's part of a letter from Paul telling Christians not to fall out with one another over small things, on which we'll all have different opinions. (In the church then, some people were happy to eat meat which had been used in pagan temples, and others weren't; some Christians were serious about fasting on certain days, and others didn't make any such rules for themselves.) Paul tells them what really matters, outlines how "kingdom" people behave to one another, and then tells them what the real heart of the kingdom is all about. And it isn't food and drink.
Go to the review to check you understand and remember
Go to points 4 and 5 for additional teaching
Go back to the main resources page to do something completely different