The Bible gives an excellent example of this. The character is Jacob. Jacob had deceived his father to get the blessing that belonged to his older brother Esau (see Gen. 27). Jacob then had to flee for his life because Esau wanted to kill him (Gen. 27:42).
Several years later, the Lord said to Jacob, "Return to the land of your fathers and to your family, and I will be with you" (Gen. 31:3). This meant Jacob would have to confront his brother whom he feared all those years. The Scripture says, "Jacob was terrified" (Gen. 32:7). He was obviously feeling weak in faith. There are times where I too have a lack of faith.
It is interesting that our true enemy, the devil, has not changed after all these years. In Genesis 32:10, Jacob said, "I am not worthy..." The enemy always wants to remind us of our failures. When this happens, I just remind myself, "Christ made us right with God; he made us pure and holy, and he freed us from sin (1 Cor. 1:30). But our High Priest offered himself to God as a single sacrifice for sins, good for all time" (Heb. 10:12) (NLT).
What Jacob did next is important. The Bible says in Genesis 32:9 (NLT), "Then Jacob prayed, 'O God of my grandfather Abraham, and God of my father, Isaac—O Lord, you told me, 'Return to your own land and to your relatives.' And you promised me, 'I will treat you kindly.'". He prayed to God and reminded Him what He said.
God talks to us all the time. A dream from God will come from at least two different sources (see Gen. 41:32, 2 Cor. 13:1) and will always line up with the Word of God. If God has given you a dream that meets this criteria, keep reminding Him, especially when you feel weak in faith.
In the end, God blessed Jacob and gave him a new name too. The Bible says, "Thy name shall be called no more Jacob, but Israel: for as a prince hast thou power with God and with men" (Gen. 32:28, KJV). Jacob means "wrongfully takes hold" (see Gen. 25:26), Israel means "prince with God".
The name change tells us; someone grabs what does not belong to them [Jacob] and becomes a prince with God [Israel]. The Bible says we have been made kings (Rev. 1:6). This is the gift of salvation. Jacob was a picture of a modern day Christian.
If you have a dream, remind God what he said. You will see it come to pass, no matter how large it is---our God really is a BIG GOD, nothing is too difficult for Him.