How can I tell if I'm really hearing God or if it's just my own thoughts, or even Satan?

from the old testament

• In the Old Testament, God often spoke through prophets, dreams, or direct revelation, but He also gave His people standards to test whether a message was truly from Him. Deuteronomy 13:1-3 says: “If a prophet or a dreamer of dreams arises among you and gives you a sign or a wonder, and the sign or wonder that he tells you comes to pass, and if he says, ‘Let us go after other gods,’ which you have not known, and let us serve them, you shall not listen to the words of that prophet or that dreamer of dreams.” Even if a sign or prediction comes true, if the message leads people away from the one true God, it is not from Him. God’s voice will never contradict His revealed truth or lead people into idolatry or sin.
• Another test of whether we are hearing God is whether the message leads to obedience and reverence for Him. In the Old Testament, true prophets called people to repentance and faithfulness. Jeremiah 23:21-22 warns of the difference between good and false prophets: “I did not send the prophets, yet they ran; I did not speak to them, yet they prophesied. But if they had stood in my council, then they would have proclaimed my words to my people, and they would have turned them from their evil way, and from the evil of their deeds.” God’s true voice convicts of sin, calls for repentance, and leads to righteousness.
• Those who walk closely with God learn to recognize His voice. For example, the young prophet Samuel initially didn’t know it was God speaking to him (1 Samuel 3:9-10). Samuel had to be taught how to respond to God’s voice. Discernment can grow over time as we walk with God and learn to listen.

from the new testament

• God most clearly and commonly communicates directly with us through His Word, the Bible (2 Timothy 3:16-17; Hebrews 4:12). He may also use godly people, such as a friend or mentor, to give wise counsel (see Proverbs 12:15; Proverbs 11:14), as well as prayer (see Jeremiah 33:3; Philippians 4:6-7) and circumstances (Romans 8:28; Acts 16:6-10) to guide and speak to us.
• In 2 Corinthians 10:5, we are told to "take every thought captive to obey Christ." We must actively filter our thoughts through God’s truth, checking them with Scripture so we can discern His voice and reject anything that contradicts His will.
• To discern whether we are hearing God or our own thoughts or even Satan, we must understand what God has already communicated with us through His Word, the Bible: "All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work" (2 Timothy 3:16-17).
• When God’s Word is not clear about our specific circumstance, we can pray. James 1:5 tells us that when we ask for wisdom, God will grant it, but we must believe, not doubt (James 1:6).
• When Christians listen for the Holy Spirit, we should have faith that He is with us always (John 14:16-17; Romans 8:11; see also Psalm 139:7-8). The Holy Spirit is our advocate (Romans 8:26-27; John 14:26) and desires to point us into all truth (John 16:13).
• God tells us to test the spirits (1 John 4:1). Not everything we hear or think is from God.

implications for today

Though the Bible is full of God's will, we face decisions, big and small, nearly constantly that are not spelled out in Scripture. Where should we live? Where should we work? How much should we volunteer and where?

The Bible may not address our specific circumstance, but it gives us principles that we can apply to any circumstance. Regular Bible reading helps us to apply the wisdom of its principles.

To tap into the Bible’s wisdom, though, we must devote time to reading and understanding it. Our modern world is full of noise, distractions, and diversions to distract us from God's will (1 Peter 5:8). We must create rhythms of quiet and spend time in God’s Word, allowing the Holy Spirit to help us understand Scripture.

We should also spend time with the Lord in prayer, asking Him to make clear what we need to know or do. We can ask ourselves some of these kinds of questions:

Is what I am "hearing" confusing or vague? God does not cause confusion, He brings peace (1 Corinthians 14:33).

Does the prompting or thought I received go against God's Word? God does not contradict Himself.

Will my decision lead to sin? God will not lead us to sin or be sneaky: "But I say, walk by the Spirit, and you will not gratify the desires of the flesh" (Galatians 5:16).

God wants to help you make decisions that honor Him. Jesus said, about Himself, "When he has brought out all his own, he goes before them, and the sheep follow him, for they know his voice" (John 10:4). The better we know our Good Shepherd, the better we'll be able to discern His voice. Learn to listen to His leading. Practice using discernment and comparing things with God’s Word. Pray for wisdom. Study the Bible. Seek confirmation from others you trust. Abide in and walk with God. And remember: God delights in guiding His children who truly want to follow Him (Psalm 32:8; Proverbs 3:5-6).