When Jesus was baptized, God said,

and behold, a voice from heaven said, “This is my beloved Son, with whom I am well pleased.”

Matthew 3:17, ESV

About six weeks later, Satan suggests,

But he answered, “It is written,
“ ‘Man shall not live by bread alone,
but by every word that comes from the mouth of God.’ ”

Matthew 4:4, ESV
(Quoting Deuteronomy 8.3)

When God has told me that I have been adopted as his child (See
John 1.12-13), I don’t need to question. I must trust that His word is true. I may choose to live outside His will, but His love for me does not need to be questioned. We must trust “every word that comes from the mouth of God.”