Romans 18-24 For the wrath of God is unveiled from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness; *  
Because that which may be known of God plainly known among them; for God has made it visible it to them. Note For the invisible things of Him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse: Because, when they knew God, they did not glorify Him as God, neither were thankful; but they became vain in their imaginations, and their foolish heart was darkened. The Sin Professing themselves to be wise, they became fools, And changed the glory of the incorruptible God into an image made like to corruptible man, and to birds, and four-footed beasts, and creeping things. Therefore God also gave them up to uncleanness through the desire for forbidden things that is within their own hearts, to dishonor their own bodies between themselves

If you really want to obey God, you will know if what I [Jesus] teach comes from God or from Me John 7:17

My sheep listen to my voice; I know them, and they follow me. John 10:27  

Trust in the Lord with all your heart, and lean not on your own understanding; in all your ways acknowledge Him, and He shall direct your paths. Proverbs 3:5

Then said they to him, What shall we do, that we might work the works of God? Jesus answered and said to them, This is the work of God, that ye believe on him whom he hath sent. John 6:28-29

Today, if you hear his voice, do not harden your hearts as you did in the rebellion. Hebrews 3:15

More Scripture through which God says that He speaks to us and leads us.