My dear children, you come from God and belong to God. You have already won a big victory over those false teachers, for the Spirit in you is far stronger than anything in the world. These people belong to the Christ-denying world. They talk the world’s language and the world eats it up. But we come from God and belong to God. Anyone who knows God understands us and listens. The person who has nothing to do with God will, of course, not listen to us. This is another test for telling the Spirit of Truth from the spirit of deception. 1 John 4:4 MSG https://bible.com/bible/97/1jn.4.4.MSG
Sometimes we can hear it when someone else talks about something that they have an opinion about. The truth is evident in the words that they speak about their beliefs. Then you come across someone else who is not speaking of what they know but what they want from you. Deception can take all kinds of shapes and change them to fit whatever the agenda may be, make sure you know the Bible well enough to spot the difference.