First, you should pray. Just as prayer is important in the kitchen and before a meal, prayer is important for class. You should pray as you prepare for class. A short prayer before class is also appropriate. Pray for your students to live well, learn well, and grow into thoughtful individuals.
Second, you should be aware of the price you are paying for your teaching. Time preparing for class could be time away from other important aspects of life that you want to participate in. For me, teaching and class preparation is time away from my family. I do enjoy teaching, but I do pay a price for it.
Third, prepare for class. This is one of the mantras I remember from graduate school. Prepare, prepare, prepare! Class preparation, more than any other aspect of teaching, is the biggest witness of one's faith in Christ to students. As students imagine themselves effective English speakers as a result of excellent teaching and effort, they grow and change as people. Some of them will come back and say thank you for the hard work you put into class and they may ask you why. It is then that you can share your faith. We need to strive to be excellent in order to be an effective teacher and an effective evangelist.
Fourth, praise God. I have started with prayer and I am ending with praise. Praise God for your opportunities to teach. Praise God for your students, even the difficult ones. Praise God for your opportunities to grow and change as a teacher. The way of teaching is not always positive but praise allows us to reflect on its meaning. You might be shaking your head because something went wrong in class or with your teaching. God is in charge of it all.
The Christian way of boiling eggs may not be a silly question after all. It prepares our hearts and minds to enjoy something simple, a boiled egg. As you pray, pay a fair price, prepare for class, and praise God, the classroom will become a simpler place where you enjoy relationships with your students.