Ligonier Ministries is offering several free online video teaching series by R.C. Sproul. Below is the first video from each series that are available to watch for free.
The Holiness of God
1. The Importance of Holiness 2. The Trauma of Holiness
3. Holiness and Justice 4. The Insanity of Luthe
There are more free online teachings by Dr. Sproul at the Teaching Series section of Ligonier’s website.