IT IS obvious that there are objects to attain which we ought not to pray. We shall try to specify them as follows:
1. We may not pray for things that are evil or injurious in themselves, or injurious on account of circumstances. Amongst these are comprised all those that are opposed to the salvation of the person praying, or of some one else. It is contrary to the very idea of prayer that God should grant to His creature anything evil, anything that is in itself, and not only by abuse, harmful. Prayer, according to the rules of morality, must have for its object only the attainment of whatever is good and profitable, and only then is it heard by God.
2. Things completely indifferent are not comprised in the efficacy of prayer. Hence prayer imploring for temporal goods is heard only inasmuch as they relate to the salvation of souls. Reason, as well as faith, teaches us that God orders all His actions first for the promotion of His glory, and secondly for the salvation of souls. Matters, therefore, that are either in general, or on account of circumstances, positively indifferent, must be excluded from the general plan of God's providence when there is question of His positive agency, and not simply of His permission. It is obvious that temporal goods, such as health, wealth, etc., are classed with things indifferent, in as far as they are not connected with the moral order.
Thus considered, the various goods of the temporal order do, or at least may, under certain conditions, co-operate unto man's salvation, and then they belong to the supernatural order. As such, the efficacy of prayer in their regard must be judged according to the principles applying to the latter.
3. All those things which any one can obtain himself without extraordinary effort, are not comprised within the scope of prayer. This restriction results from the very nature of prayer. Obviously, prayer is not the only means by which man can obtain those things which, on the one hand, he momentarily does not possess, and which, on the other hand, are necessary or advantageous for his supernatural life. As a rule, man can, by labor and application, procure his sustenance. Persons unable to work can have recourse to the charity of their fellow-men, and will, as a rule, find the necessary assistance. In regard to salvation, it must first be ascertained whether in many or at least in some cases, the faithful co-operation with the graces which God gives to all men is not sufficient.
Considered from this view, we may, and even must, in a certain sense say: When there is question of attaining specified goods and specified graces, prayer is often not the primary, but only the secondary and subordinate means. From this premise follows that God in His wise providence does not have regard for our prayer when we easily can help ourselves, either by our own exertion and industry, or by the faithful cooperation with graces already received, or by the reception of the holy sacraments. This self-evident idea is expressed in Holy Scripture as follows, "Because of the cold the sluggard would not plow; he shall beg therefore in the summer, and it shall not be given him" (Prov. xx. 4). For this reason formal miracles are, as a rule, not to be expected from the efficacy of prayer. God ordained the world and its course in such a manner, that mankind in general and each individual in particular can be provided, without the intervention of a miracle, with all things necessary for their temporal and eternal welfare.
Theologians, therefore, teach that to ask God for a miracle, generally, is the same as to tempt Him. This rule, however, admits of exceptions. And if we may, in exceptional cases, ask for miracles, we may, logically, expect them; for miracles in general are not excluded from the plan of divine Providence. They are rather an essential part of the existing order of God's government of the world. At most we may say: As miracles of their nature belong among the extraordinary manifestations of Providence, they are not obtained by the prayer of each and every one, but only in exceptional cases.
However, if we consider how feeble and helpless man's nature is, even with the assistance of divine grace, we may not apply the above principles too strictly. This, for the following reason: Cases in which we can not help ourselves with the aid of the grace given us are rare. Therefore God gives us, in reward of our confident prayer, not only that which is strictly necessary, but also that which is profitable and conducive to our welfare. This being so, the logical deduction is, that God is willing to hear our prayer not only when we, of ourselves, are totally incapable of helping ourselves, but also when great difficulties beset us in this our self-help. Hence, in a certain sense, we may maintain that in the work of our salvation prayer and its efficacy must be considered, together with the sacraments, as one of the chief means, and not as a mere accessory.
This limitation of the main principle is founded on the generality of the divine promises concerning the hearing of prayer, and on the great goodness and bounty of God in which these promises originated. When man, making use of all the means placed at his disposal, can not help himself, a cry for help is sent to Heaven is not presumptuous or unreasonable, and therefore the hope of being heard is not unfounded or in vain.