There is a Biblical principle that calls for two or three witnesses as confirmation of a thing. God Himself is not exempt from this principle and even in sending and revealing His Son, He has given us three witnesses to attest to the Truth.
6 And Jesus Christ was revealed as God’s Son by his baptism in water and by shedding his blood on the cross—not by water only, but by water and blood. And the Spirit, who is truth, confirms it with his testimony. 7 So we have these three witnesses—8 the Spirit, the water, and the blood—and all three agree. 9 Since we believe human testimony, surely we can believe the greater testimony that comes from God. And God has testified about his Son. 10 All who believe in the Son of God know in their hearts that this testimony is true. Those who don’t believe this are actually calling God a liar because they don’t believe what God has testified about his Son. (1 John 5:6-10, NLT)
God Himself has provided three witnesses so that we might know assuredly that Jesus truly is the Son of God. Let us wholeheartedly receive them as true and refuse to be found accusing the Father of lying.