We know the general will of God by His Word.
We know the specific will of God by His voice.
#1 God wants to talk to me
John 15:15 I don't call you servants anymore, because a servant doesn't know what his master is doing. But I've called you friends because I've made known to you everything that I've heard from my Father.
One of the marks of a personal relationship with someone is communication.
#2 I can hear God’s voice
As a Christian, hearing God is not something you do, it's someone you are.
John 10:1-4 (NKJV) “Most assuredly, I say to you, he who does not enter the sheepfold by the door, but climbs up some other way, the same is a thief and a robber.