'Certainly' in the Bible

Desiring to be teachers of the law, though they have no knowledge of what they say or of the statements which they make so certainly.

And most certainly, the mystery of godliness is great:He was manifested in the flesh,vindicated in the Spirit,seen by angels,preached among the nations,believed on in the world,taken up in glory.

For we brought nothing into the world, and we certainly can't carry anything out.