he that craves for this thing and that thing, as a token for good at the hand of the Lord, stands in danger of perishing from want of faith.

"But [Thomas] said to them, 'Unless I see in his hands the mark of the nails, and place my finger into the mark of the nails, and place my hand into his side, I will never believe.'”  John 20:25
Dear friends, if you began to seek signs, and if you were to see them, do you know what would happen? Why, you would want more; and when you had these, you would demand still more. Those who live by their feelings judge of the truth of God by their own condition. When they have happy feelings, then they believe; but if their spirits sink, if the weather happens to be a little damp, or if their constitution happens to be a little disordered, down go their spirits, and, straightway, down goes their faith.
He that lives by a faith which does not rest on feeling, but is built upon the Word of the Lord, will remain fixed and steadfast as the mount of God; but he that craves for this thing and that thing, as a token for good at the hand of the Lord, stands in danger of perishing from want of faith.
He shall not perish, if he has even a grain of living faith, for God will deliver him from the temptation; but the temptation is a very trying one to faith.
Crave, therefore, no sign. If you read a story of a person who saw a vision, or it you hear another declare that a voice spoke to him—believe those things, or not, as you like; but do not desire them for yourself.
These wonders may, or may not, be freaks of the imagination. I will not judge; but we must not rely upon them, for we are not to walk by sight, but by faith.

A Sermon  (No. 2061) C. H. SPURGEON

"Then [Jesus] said to Thomas, 'Put your finger here, and see my hands; and put out your hand, and place it in my side. Do not disbelieve, but believe.' Thomas answered him, 'My Lord and my God!' Jesus said to him, 'Have you believed because you have seen me? Blessed are those who have not seen and yet have believed.'"   John 20:27-29