“My sheep hear My voice, and I know them, and they follow Me.” John 10:27

In order to hear the voice of the Lord, you need to believe in Him. There can be no unbelief; unbelief is an evil heart.

“Beware, brethren, lest there be in any of you an evil heart of unbelief in departing from the living God;” Hebrews 3:12

If you have unbelief, ask the Lord to help you to believe.