All prayers are accepted by God because God hears all our prayers, but God only answers our prayers when God decides to do so.
“O thou who art the fruit of My Tree and the leaf thereof! On thee be My glory and My mercy. Let not thine heart grieve over what hath befallen thee. Wert thou to scan the pages of the Book of Life, thou wouldst, most certainly, discover that which would dissipate thy sorrows and dissolve thine anguish.
Know thou, O fruit of My Tree, that the decrees of the Sovereign Ordainer, as related to fate and predestination, are of two kinds. Both are to be obeyed and accepted. The one is irrevocable, the other is, as termed by men, impending. To the former all must unreservedly submit, inasmuch as it is fixed and settled. God, however, is able to alter or repeal it. As the harm that must result from such a change will be greater than if the decree had remained unaltered, all, therefore, should willingly acquiesce in what God hath willed and confidently abide by the same.
The decree that is impending, however, is such that prayer and entreaty can succeed in averting it.