Verses with the word assurance in the New Testament (5 verses):

Acts 17:31
Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead.

Colossians 2:2
That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ;

1 Thessalonians 1:5
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.

Hebrews 6:11
And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end:

Hebrews 10:22
Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.