Spiritual deception is real, even in the Church. We must understand that only God can protect us from being deceived. We cannot rely on our own intellect or intuition. Spiritual discernment is a gift from God. We need to ask him for Godly wisdom:

If any of you is lacking in wisdom, ask God, who gives to all generously and ungrudgingly, and it will be given you.   (James 1:5)

The Apostle Paul was concerned that those in the Church might be led astray:

But I am afraid that as the serpent deceived Eve by its cunning, your thoughts will be led astray from a sincere and pure devotion to Christ. For if someone comes and proclaims another Jesus than the one we proclaimed, or if you receive a different spirit from the one you received, or a different gospel from the one you accepted, you submit to it readily enough.   (2 Corinthians 11:3-4)

In fact, the Church in Galatia, which Paul help found, was led astray. Paul wrote this Church:

I am astonished that you are so quickly deserting the one who called you in the grace of Christ and are turning to a different gospel — not that there is another gospel, but there are some who are confusing you and want to pervert the gospel of Christ. But even if we or an angel from heaven should proclaim to you a gospel contrary to what we proclaimed to you, let that one be accursed! As we have said before, so now I repeat, if anyone proclaims to you a gospel contrary to what you received, let that one be accursed!   (Galatians 1:6-9) 

Satan discovered that he could not stop the spread of the Gospel by force. Thus, he would infiltrate the Church with a false Gospel. He cleverly disguised it at first, but over time he would steadily lead people astray. We have significant evidence today that his plan has been effective in many of our churches.

To reject these false teachings we must first love and seek the truth. The Apostle wrote:

The coming of the lawless one is apparent in the working of Satan, who uses all power, signs, lying wonders, and every kind of wicked deception for those who are perishing, because they refused to love the truth and so be saved. For this reason God sends them a powerful delusion, leading them to believe what is false, so that all who have not believed the truth but took pleasure in unrighteousness will be condemned.   (2 Thessalonians 29-12)

In some of the Pentecostal churches, lying wonders have taken over. When we start worshipping the wonders and not the wonder maker, we are in grave trouble.

Angels have been elevated in some churches. People pray to them and call upon them to manifest themselves. The messengers of God have become the message in some churches. Paul wrote:

Do not let anyone disqualify you, insisting on self-abasement and worship of angels, dwelling on visions, puffed up without cause by a human way of thinking, and not holding fast to the head, from whom the whole body, nourished and held together by its ligaments and sinews, grows with a growth that is from God.   (Colossians 2:18-19)

The Apostle John warns that we must believe in the virgin birth of Jesus. We must believe that he is a physical being. We must believe in his bodily resurrection.

Many deceivers have gone out into the world, those who do not confess that Jesus Christ has come in the flesh; any such person is the deceiver and the antichrist! Be on your guard, so that you do not lose what we have worked for, but may receive a full reward.   (2 John 1:7-8)

If we keep to the true faith, we will be persecuted. People will reject us. If we need the praise of people more than the praise of God, we become very vulnerable to deception. If we do not meditate on the holy scriptures, we will have little defense against falsehood and lies. Paul writes:

Indeed, all who want to live a godly life in Christ Jesus will be persecuted. But wicked people and impostors will go from bad to worse, deceiving others and being deceived. But as for you, continue in what you have learned and firmly believed, knowing from whom you learned it, and how from childhood you have known the sacred writings that are able to instruct you for salvation through faith in Christ Jesus. All scripture is inspired by God and is useful for teaching, for reproof, for correction, and for training in righteousness, so that everyone who belongs to God may be proficient, equipped for every good work.   (2 Timothy 3:12-17)