The angels are Allah's creatures, He made them from light, and they're hidden from us. We can't see them, but we must believe in them because believing in them is one of The Pillars of Faith. As it was mentioned in the Quran.
*We will start with their creation, God created the angels some with two wings and some with three wings and some with four wings, and some with more than four wings, and that for the immediate execution of the commands of God, especially that commands them for different jobs and they do not disobey God commands and they do what they are commanded to do. God says " All praise is(due) to Allah, Creator of the heavens and the earth,(who) made the angels messengers having wings, two or three or four. He increases in creation what He wills. Indeed , Allah is over all things competent." Surat Fatir 1
*Angels have great relationship with human beings for there are two angels with every human being, whether he is a believer or an infidel , and one of the two angels on the right side of a human, and he writes the good deeds, and the second angel on the left side of a human and he writes the bad deeds . God says:"And we have already created man and know what his soul whispers to him, and We are closer to him than (his) jugular vein. Surat Qaf 16-18
Because God gives some of his creatures capabilities abilities more than others, God gave the angels the ability to be in different shapes and change into human shape, as it happened to Mary mother of Jesus when one of the angels came to her in human shape, and blew air onto her dress, came to she conceived Jesus son of Mary, peace be upon them. God says: "And mention in the book(Qur'qn) O Mohammed the story of Maryam(Mary), when she withdrew in seclusion from her family to an eastern place. 16, She placed a screen (to hide herself) from them ; then We sent to her Our conveyer (Gabriel) and he appeared before her as a human in all respect. 17,She said "Verily I seek refuge from the Most Gracious (God)against you, if you were pious.18,The angel said: "I am only a messenger from your God to announce to you the gift of a righteous son"19,
In spite of that all angels are obedient to God, there are some degrees of preference , some are better than others in God choice as those who carry the Throne.
The angels have good relationship with the believers that becauseIn spite of their status and their closeness to God they all pray to God to forgive the believers.
If the angels pray for you and ask God for forgiveness for you, you must love them and do not be hostile to them and consider them as your enemies.
In addition to the prayer of the faithful angels for believers , the angels fought with the Muslims against the unbelievers, as it happened in the Battle of Badr.
And angels abound in good places and around holy studying sittings and important worshipping time, such as the Night of Qadr in Ramadan
And the angels as they are with believers in life time , they'll be with them at their death time. And the angels are with them in the day of judgment And they'll live with the faithful people forever and ever.
But the infidels have different relationship with the angels, there are two angels with all human including the infidel, one writes good deeds and the other writes his bad deeds.
And because God is wise; he was able to put the good believer in paradise and put the atheist in the hell fire from the beginning of their creation, but God created this world for the sake of testing humans and so they will testify against themselves, and make the test is the belief in the unseen, as faith in Allah and the Last Day and the angels and the heavenly books and the apostles and to the extent all these things are not seen by people, but God is created around us many clear proofs of the existence of those super natural things, so who believes it is safe and goes to Paradise, and who disbelieves in it goes to the hellfire.
So God will not show this super natural things to humans; because if they appeared they all will believe forcibly , and this is not what God wants, but God wants every human to believe of their own free will and choice, but the infidels violate the good thinking and and so they always demand to see the unseen and the vision of angels, o believe in them Although the basic principle is that human beings do not see angels, but angels can be seen in rare cases, if seen by a Prophet of prophets, and so on The fact is that the human who was misguided judgment of God will remain misled and he will not believe in angels, even if the unseen revealed to him and he saw them And it is no wonder that the man who does not believe in angels he sometimes worships them and give them feminine name.
So the disbelievers are suppose not to worship angels, for two reasons are:
1-Because the angels innovate God because they fear Him.
2-Because the angels themselves will keep silent on the day of resurrection in the presence of God the greatest.
And when disbeliever death time comes the angels take his soul of his body, and blame and even beat his face and hit back But in the Day of Judgment, great strong angels accompany the disbelievers to the hellfire s They tease , annoy and torture them.