I was recently reflecting on the word supplication which is defined in the dictionary as: to make a humble entreaty.
I would expand this to: making a humbled, obedient entreaty with faith in the heart.
Note the change from humble to humbled. I did this to indicate direction. Many humble themselves before another to gain favor in their sight but are not humbled by them. That form of humility is joined to an aspiration. God refuses such attempts.
Adding obedient speaks to being willing to receive instruction concerning the due course one must follow as established by the terms set by the one being petitioned. A great example of this can be seen in the account of Naaman the leper in 2 Kings 5.
Adding "with faith in the heart" speaks of being joined through sanctified contact. Faith joined to Christ meets the expectations of God perfectly and He extends His scepter of righteousness to us that we may draw near to Him to make our petitions known and so that He can inspect and nurture His good fruit within our souls.
So by learning to function in the Spiritual priesthood of Christ with faith made perfect by sanctified contact with Him, we have our prayers answered and He fulfills His joy in our hearts.