Is hope alone for the supplication to be answered and for forgiveness sufficient, without complete certainty, for it to be considered as having a good opinion of Allah?

Allah Almighty promised to answer prayers in His words: "Call upon Me; I will respond to you" and "I respond to the invocation of the supplicant when he calls upon Me." The prayer of a Muslim is answered as long as he does not pray for a sin, or for the severance of kinship ties, or if he is not impatient. Among the etiquettes of supplication is for the Muslim to supplicate with certainty of being answered, for Allah does not answer the prayer from a heedless, inattentive heart. Certainty means that the supplicant has complete trust that Allah is capable, generous, and all-knowing, and that He will answer his prayer. Every supplication free from sin and the severance of kinship ties, its owner is granted one of three things: either his prayer is hastened, or Allah stores it for him in the Hereafter, or He averts from him an equivalent evil. The required certainty is for the supplicant who has fulfilled the conditions to be certain that Allah will grant him one of these three qualities.