Instructions given by Joseph Smith the Prophet, at Nauvoo, Illinois, February 9, 1843, making known three grand keys by which the correct nature of ministering angels and spirits may be distinguished.

1–3, There are both resurrected and spirit bodies in heaven; 4–9, Keys are given whereby messengers from beyond the veil may be identified.

1 There are two kinds of beings in heaven, namely: Angels, who are resurrected personages, having bodies of flesh and bones—2 For instance, Jesus said: Handle me and see, for a spirit hath not flesh and bones, as ye see me have.
Note: Jesus Christ is not an angel.
For to which of the angels did He ever say: “You are My Son, today I have begotten You”? And again: “I will be to Him a Father, and He shall be to Me a Son”? But when He again brings the firstborn into the world, He says: “Let all the angels of God worship Him.” And of the angels He says: “Who makes His angels spirits and His ministers a flame of fire.” But to the Son He says: “Your throne, O God, is forever and ever; A scepter of righteousness is the scepter of Your kingdom. You have loved righteousness and hated lawlessness; Therefore God, Your God, has anointed You with the oil of gladness more than Your companions.” And: “You, LORD, in the beginning laid the foundation of the earth, and the heavens are the work of Your hands. They will perish, but You remain; And they will all grow old like a garment; Like a cloak You will fold them up, and they will be changed. But You are the same, and Your years will not fail.” But to which of the angels has He ever said: “Sit at My right hand, till I make Your enemies Your footstool”? Are they not all ministering spirits sent forth to minister for those who will inherit salvation? Hebrews 1:5-14

3 Secondly: the spirits of just men made perfect, they who are not resurrected, but inherit the same glory. 4 When a messenger comes saying he has a message from God, offer him your hand and request him to shake hands with you. 5 If he be an angel he will do so, and you will feel his hand.
Note: Believers will test the message not a handshake.
Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world. By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world. 1 John 4:1-3

6 If he be the spirit of a just man made perfect he will come in his glory; for that is the only way he can appear—7 Ask him to shake hands with you, but he will not move, because it is contrary to the order of heaven for a just man to deceive; but he will still deliver his message.
Note: Believers will test the message not a handshake.
O foolish Galatians! Who has bewitched you that you should not obey the truth, before whose eyes Jesus Christ was clearly portrayed among you as crucified? This only I want to learn from you: Did you receive the Spirit by the works of the law, or by the hearing of faith? Are you so foolish? Having begun in the Spirit, are you now being made perfect by the flesh? Have you suffered so many things in vain—if indeed it was in vain? Therefore, He who supplies the Spirit to you and works miracles among you, does He do it by the works of the law, or by the hearing of faith? — just as Abraham “believed God, and it was accounted to him for righteousness.” Therefore, know that only those who are of faith are sons of Abraham. And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel to Abraham beforehand, saying, “In you all the nations shall be blessed.” 9 So then those who are of faith are blessed with believing Abraham. Galatians 3:1-9

8 If it be the devil as an angel of light, when you ask him to shake hands he will offer you his hand, and you will not feel anything; you may therefore detect him. 9 These are three grand keys whereby you may know whether any administration is from God.
Note: Believers will test the message not a handshake.
You, therefore, beloved, since you know this beforehand, beware lest you also fall from your own steadfastness, being led away with the error of the wicked; but grow in the grace and knowledge of our Lord and Savior Jesus Christ. To Him be the glory both now and forever. Amen. 2 Peter 3:17-18