1 John 5:10
(He who believes on the Son of God, has the testimony in himself. He who believes not God, has made him a liar, because he has not believed the testimony, which God has testified concerning his Son.)
1 John 5:20
Moreover, we know that the Son of God has come, and has given us understanding, that we might know him that is true; and we are in him that is true-in his Son Jesus Christ. This is the true God, and the eternal life.
Revelation 3:7
And by the messenger of the congregation in Philadelphia, write: These things says the Holy One, the True One; who has the key, the Son of David; he who opens and no man shuts; and shuts, and no man opens: