“For our gospel did not come to you in word only, but also in power, and in the Holy Spirit and in much assurance, as you know what kind of men we were among you for your sake.” – 1 Thes. 1:5
In much assurance: abundant confidence, deep conviction, lit. “fully come to bear.”
The Gospel of Jesus Christ = Word + power + Holy Spirit + full assurance.
A Verse A Day 