Because Jesus' word and work bear indisputable testimony to who he is, we must come to him for life.

John 5:31-40

[31] If I alone bear witness about myself, my testimony is not true. [32] There is another who bears witness about me, and I know that the testimony that he bears about me is true. [33] You sent to John, and he has borne witness to the truth. [34] Not that the testimony that I receive is from man, but I say these things so that you may be saved. [35] He was a burning and shining lamp, and you were willing to rejoice for a while in his light. [36] But the testimony that I have is greater than that of John. For the works that the Father has given me to accomplish, the very works that I am doing, bear witness about me that the Father has sent me. [37] And the Father who sent me has himself borne witness about me. His voice you have never heard, his form you have never seen, [38] and you do not have his word abiding in you, for you do not believe the one whom he has sent. [39] You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me, [40] yet you refuse to come to me that you may have life.