The Bible is full of verses that tell us to NOT be afraid, to NOT fear anything and to trust in God. But… there is 1 verse, the only verse in the entire bible that tells us that there is something that we should fear.
Have a look for yourself, throughout the entire bible God always says “Fear not for I am…”. Except in Hebrews 4:
Therefore, since a promise remains of entering His rest, let us fear lest any of you seem to have come short of it. 2 For indeed the gospel was preached to us as well as to them; but the word which they heard did not profit them,[a] not being mixed with faith in those who heard it. 3 For we who have believed do enter that rest… – Heb 4