The symbol of IHC may be one of the most misunderstood Christian symbols. The most important thing to understand about this symbol is that it is not English. Thus the letters are not actually I, h, or c.
The IHC symbol is understood to be Greek, making the letters an iota, an eta, and a final sigma. These are the first, second, and last letters of the name "Jesus." The bar frequently appearing over the lower case h (a Greek eta) is understood to indicate the omission of the other letters. It is also often combined with the letter to form a Latin Cross.
In short, this symbol is a reminder of the name "Jesus."
(There are differing opinions on the relationship between IHC and IHS and their intended meanings. I have chosen these interpretations as doing so provides multiple avenues for teaching.)
This symbol can be found frequently on communion tables or vestments. Look for it in or around the front of your worship space. Though it can be combined with other symbols, it is more frequently found by itself. Be careful not to confuse this symbol with the IHS.
The name Jesus is a form of the name Joshua. Read Deuteronomy 31.7-8, and 31.23. Who was Joshua? What would you expect from someone who shares his name?
Next, Read Matthew 1.18-25. Where did Joseph get the idea for the name Jesus? What is the significance of the name?
Finally, read Philippians 2.1-11. In what ways would Jesus have met the expectations of people who expected him to be like Joshua. How would he have surprised them? Once more, what is the significance of the name of Jesus in this passage?
This symbol offers a wonderful way to preach any of the passages above, and the Philippians passage in particular.
Highlighting the IHC symbol in a sermon could allow you to draw connections and contrasts between the story of Joshua and the life of Christ.
It could also provide a way to discuss the importance of names in general, and being known by name. In this way, the story of Jacob wrestling the angel in Genesis 32.24-29 would also be appropriate.
Because of its ties to the beginning of Matthew, the IHC symbol could easily be used during advent or Christmas.
Since it is simply an abbreviation of the name Jesus, it could also be used easily during ordinary time as well