'Proof' in the Bible

For to this end also did I write, that I might know the proof of you, whether ye are obedient in all things.

how that in much proof of affliction the abundance of their joy and their deep poverty abounded unto the riches of their liberality.

Show ye therefore unto them in the face of the churches the proof of your love, and of our glorying on your behalf.

seeing that ye seek a proof of Christ that speaketh in me; who to you-ward is not weak, but is powerful in you: