An invocation or to invoke (from the Latin verb invocare “to call on, invoke, to give”) may take the form of:
To invoke; to stimulate or to stir up nature and the attributes of spirituality (angels, supernatural, spiritual beings, spiritual presence pysical and cosmic energies) via the art of speaking, utterence of words, prophesying or prayer.
Supplication or prayer. 
In the negative realm which pertains to pagan practices, this could mean spell, profanity or incantation, which aims at the stiring up of evil spirits.

Self-identification of one’s requests declared via prayers which is accompanied by a sacrifice during a certain season or given time.

As a supplication or prayer it implies to call upon God. In pagan practices to invoke or invocation implies to call upon a god or goddess or many gods etc. 
To speak words with the intention of provoking the spiritual presence or realm into action. <they gave him a name which means; “God is with us”> 
A form of possession. The art of puting ideas into one’s mind or the universes..
<There prayers have created an atmosphere of peace and hope in our neighbourhood>
<when that man speaks profanity, you feel a sence of fear and confusion in the atmosphere>.
Command or conjuration.
Invocation is a Self-identification with certain spirit.

Article written by Conscious lifestyle..