Truly, it is a noble deed to look into the God's Word with the intent of sharing the Good News with others (Acts 17:11). If you find that you have decided to teach a Bible lesson, you might have, also, found yourself asking, "What should I do first?" Feeling, perhaps, a little overwhelmed with the task at hand, the first thing to do is pray! All faithful Old Testament and New Testament servants of God remembered from whom they received their strength and that was from God. (Ex. 15:1, 2; Jud. 16:28; 2 Sam. 22:1, 33) You, too, can receive that strength. (Ps. 46:1; Phil. 4:6; Jas. 5:16) Pray! Pray when you are successful and pray when you are not. (1 Thess. 5:17)
Next, how well do you know the material that you are about to teach? Have you studied diligently, well enough to explain the lesson to children? (2 Tim. 2:15) How can you teach something that you know little about? Put time and effort into study!
While there are many 'helps' around (blogs such as this one, purchased lesson material, and books of man), did you open your Bible first? There is no substitute for God's Word. God's Word is what will judge us--and the children in our care--on that Last Great Day. (Jn. 12:48)
The Bible is our authority for everything we teach! (2 Tim. 3:16, 17)
Are you committed to this task? You may not love teaching 52 weeks a year, but for the time you have agreed to teach, you must be committed to doing the very best that you can. (Ecc. 9:10) While enthusiasm is a good thing, make certain the knowledge is there, too. (Rom. 10:1-3) When our hearts and minds are committed to God's work, what can stop us? (Neh. 4:6)
Finally, read the lesson...study the lesson...know the lesson...then teach the lesson to the very best of your ability! Not only will the children learn, but you will, too! God will bless you for your good efforts!