John 3:33
"He that hath received his testimony hath set to his seal that God is true."
Cross References (ranked by relevance)
Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath:
In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
But as God is true, our word toward you was not yea and nay.
Who hath also sealed us, and given the earnest of the Spirit in our hearts.
Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.