"It is a fearful thing to fall into the hands of the living God." (Hebrews 10: 31)
Once again, context is important to appreciate this verse properly.
The writer of Hebrews is warning his fellow Jewish believers that if they reject the Spirit of Grace, if they refuse to rest in the finality of Jesus' Finished Work at the Cross, the face nothing but judgment and eternal death, because there is no other way:
"Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." (John 14: 6)
Now, if you do believe on Jesus, you have nothing to fear being in His hands.
These are big hands, by the way:
"I have made the earth, and created man upon it: I, even my hands, have stretched out the heavens, and all their host have I commanded." (Isaiah 45: 12)
What is he doing with His hands today? Upholding us!
"Fear thou not; for I am with thee: be not dismayed; for I am thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness." (Isaiah 41: 10)
Guess whose names are written on those hands?
"Behold, I have graven thee upon the palms of my hands; thy walls are continually before me." (Isaiah 49: 16)
Jesus affirmed for us who believe on Him that we are safe in His hands:
"And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand." (John 10: 28)
"29My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand. " (John 10: 29)
While the writer of Hebrews warned those who do believe of the fearful wrath of God, we who believe have nothing to fear, for we are safe in God's hands.