In Sabbath School, I taught on the doctrine of providence. It led to some deep discussion regarding God's governance of all things and how that relates to man's responsibility and guilt in making real choices to sin. Good stuff!
In worship, I preached the first eight verses of 3 John. I taught that 3 John should be read as more of a pastoral epistle to Gaius, after the pattern of Paul's letters to Timothy and Titus. In the first eight verses, John repeatedly mentions things being done "in truth", so I unpacked the importance of truth in the life of the believer, and in our relationships.