1 Timothy 4:1 Now the Spirit expressly says that in latter times some will depart from the faith, giving heed to deceiving spirits and doctrines of demons
The Bible says that God created all that exists and that He created all things perfect. However, some of God's creations have chosen to rebel against Him. This is familiar to us, as each of us has ourselves chosen to rebel against God, just as our forefather Adam did. However, man was not the only creation to rebel against God. Before Adam fell, one-third of the angels God created rebelled against Him. Revelation 12:3–4
Now these fallen angels, or demons, seek to deceive mankind and lead us astray, away from God. Their teaching may seem good and righteous, but it is designed to lead people to hell.
1 Corinthians 11:13–15 For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for Satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works.
Matthew 24:24 For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.
It is typical that Satan will tell us what we want to hear instead of the truth that calls us to deny ourselves and follow Christ. 2 Timothy 4:3 In fact, Satan will even use the Bible to deceive people. He will take verses out of context and twist them to mean something they do not. He did this to Jesus when he tempted Him in the wilderness. Matthew 4:5–7
It is key therefore that Christians be discerning and not believe everything they hear. We must test everything against the Bible. It is the only source of truth. 2 Timothy 3:16–17
1 John 4:1–3 Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God: And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.