Don't worry - that is their fear-based tactic to make you back off from Scripturally critiquing something. What are those passages actually referring to? There were some Pharisees that actually saw Jesus work miracles and heard His testimony - yet they willfully attributed His works to the Devil when they clearly knew otherwise. These were lost folks - a true believer in Christ cannot do that today. Questioning some spiritual manifestations based on the Word of God is not going to get you in trouble with God - it will get you His approval and blessing, because of your obedience. It is God Himself that states the following:

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.

1 Thessalonians 5:19-22 Quench not the Spirit. Despise not prophesyings (ie. preaching). Prove all things; hold fast that which is good. Abstain from all appearance of evil.

2 Corinthians 11:3-4 But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.

2 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.

Isaiah 8:20 To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.

Matthew 7:15-20 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves. Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. Wherefore by their fruits ye shall know them.

Acts 17:11 These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so.

Philippians 1:9-10 And this I pray, that your love may abound yet more and more in knowledge and in all judgment; That ye may approve things that are excellent; that ye may be sincere and without offence till the day of Christ;

Revelation 2:2 I know thy works, and thy labour, and thy patience, and how thou canst not bear them which are evil: and thou hast tried them which say they are apostles, and are not, and hast found them liars: