'Certainly' in the Bible

"Let all the house of Israel therefore know certainly that God has made him both Lord and Christ, this Jesus whom you crucified."

But Paul said to them, "They have beaten us publicly, without a trial, men who are Romans, and have cast us into prison! Do they now release us secretly? No, most certainly, but let them come themselves and bring us out!"

What then? The assembly must certainly meet, for they will hear that you have come.

"I myself most certainly thought that I ought to do many things contrary to the name of Jesus of Nazareth.