'Power' in the Bible

For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance; as ye know what manner of men we were among you for your sake.

For the word of the Lord has resounded from you and has echoed [like thunder], not only in Macedonia and Achaia, but in every place [the news of] your [great] faith in God has spread, so that we never need to say anything about it.

And we also thank God continually for this, that when you received the word of God [concerning salvation] which you heard from us, you welcomed it not as the word of [mere] men, but as it truly is, the word of God, which is effectually at work in you who believe [exercising its inherent, supernatural power in those of faith].

For if we have faith that Jesus underwent death and came back again, even so those who are sleeping will come again with him by God's power.

But you, believers, [all you who believe in Christ as Savior and acknowledge Him as God’s Son] are not in spiritual darkness [nor held by its power], that the day [of judgment] would overtake you [by surprise] like a thief;