Verses with the word surety in the New Testament (2 verses):

Acts 12:11
And when Peter was come to himself, he said, Now I know of a surety, that the LORD hath sent his angel, and hath delivered me out of the hand of Herod, and from all the expectation of the people of the Jews.

Hebrews 7:22
By so much was Jesus made a surety of a better testament.