The Bible tells us that God is attempting to communicate with us.

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

How do we determine what is from God and what is not?
                                         
Scripture

God will not tell us to do anything that is against the commandments laid down in Scripture. The Bible is the standard of authority on all matters of faith and practice.
                                         
Prayer
 
A second way is prayer. Prayer consists of asking God for things. James said.

You do not have because you do not ask (James 4:3).

Confirmation From Others

If God is speaking to us the truth of what He is saying will be confirmed to others.
                                   
Peace Of God
 
The Bible says we are to let the peace of God rule in our hearts.

Let the peace of Christ rule in your hearts, since as members of one body you were called to peace. And be thankful (Colossians 3:15).

Summary

The believer can hear the voice of God. The Bible is God speaking to us. Prayer is our speaking to God. The peace of God will rule in our hearts when we seek to know His will.