Our ancestral, human father, Adam, delivered us and our world to satan’s hordes. So, our spiritual Father, God, patiently waited for the right time to provide the now-risen Jesus as the only effective ransom payment. But, we must individually choose to be redeemed. And, our re-alliance with God upon accepting Jesus as our Savior is referred to as redemption. It is a redemption because Jesus paid for our lives with His blood. Upon redemption, and returning to the Family, we have the rights, through Faith, to ask Abba (Strong’s concordance, G5) Father for any good thing we desire – we are family. In fact, we have a covenant agreement (Strong's concordance, H1285) with God, both as a Father and as a pledge between God and Man, a treaty, and as alliance of divine origin. The covenant allows us to pray as we wish, including for those good things which are petitions (requests, entreaties).
Even when asking for something from another human, generally one speaks in a respectful manner. Such a reverent, respectful manner (Strong’s concordance, H3374) should be characteristic of your petitions to God. However, there is nothing about our covenant relationship with God that implies that you should always be in a prone position, prostrate and begging. Contrarily, God is most generous and ready to respond favorably and abundantly. However, God has no need to foolishly waste resources upon prodigal sons and daughters who would repeatedly squander their abundance (Luke 15:11-32), to let His abundance fall as seeds onto stony ground that will never subsequently flourish (Matt 13:1-8) or to have His abundance wasted as might a lazy worker (Matt 25:14-30), hiding resources under the rock of his/her own pleasure only, not applying it to the Great Commission (Matt 28:16-18).
Some Christians are so confused about abundance and prosperity that they allege they would rather not receive it while on Earth. Some even say such things as "I would rather have Jesus than all the riches in the world." They believe themselves to sound more righteous and pious than others by making such statements. But, all the gifts given to the toddler Jesus by Wise Men, after his birth, made His family wealthy (Matt 2:1-11), although there is no Biblical evidence that they subsequently lived ostentatiously. During His ministry Jesus was prosperous enough to have a treasurer (Judas Iscariot). He paid taxes, funded the travel, board and lodging for large ministerial groups, and so on.
God allows Believers to live as paupers if such is your wish or you refuse to learn to work in the earthly systems (Hosea 4:6). But, unless you presently have spiritual gifts that allow you to turn five loaves and two fish into enough to feed more than 5,000 and yield leftovers (John 6:1-14), then you won’t be able to reach out and help others as you may wish (such as following hurricanes Katrina, Irma and Jose). So, if for no other reason, petition for wisdom, skills and knowledge development, as well as abundance even if only to assist others.
Manifestation, as referred to here, is the appearance in this world of that for which you prayed. Many are unwilling to acknowledge God’s generosity, such as expressed in John 10:10 and 3 John 1:2 because of fear and doubt (opposing their belief), or because they feel that they have yet to experience positive manifestations in their own lives, in those of their congregations, or among others close to them. People often overlook daily, simple grace and mercy they regularly experience, being most aware of miracles not yet materialized and pending responses to supplications. As you also consider others’ lives, you cannot know what they actually believe versus that which they say and demonstrate as public behavior and rhetoric.
In spite of earthly ne'er-do-wells and detractors, we are the Redeemed. Our covenant with God allows us to pray as we wish, with good petitions, to be satisfied abundantly, to develop tremendously with all manifested while we are corporeal. Of course, we will all be ultimately satisfied in Heaven. And, if at that time your memories of the past are intact and you remember a prayer-related disappointment, ask "God, why did you not…?", even if apparently lacking the wisdom to understand the response.