In summing up the application to his sermon "God The Best Portion Of The Christian", Edwards offers two ways of determining whether the Christian does indeed prefer God as the best portion over and against all other things. Edwards says there are two things "which are the surest ways to be determined in this matter, and which seem to be the best grounds of satisfaction in it."
(1) The feeling of some particular, strong, and lively exercise of such a spirit. "At such times the people of God do not need any help of ministers to satisfy them whether they have the true love of God. They plainly see and feel it; and the Spirit of God then witnesseth with their spirits, that they are the children of God. — Therefore, if you would be satisfied upon this point, earnestly seek such attainments; seek that you may have such clear and lively exercises of this spirit. To this end, you must labor to grow in grace. Though you have had such experiences in times past, and they satisfied you then, yet you may again doubt. You should therefore seek that you may have them more frequently; and the way to that is, earnestly to press forward, that you may have more acquaintance with God, and have the principles of grace strengthened. This is the way to have the exercises of grace stronger, more lively, and more frequent, and so to be satisfied that you have a spirit of supreme love to God."
(2) The other way is to inquire whether you prefer God to all other things in practice, i.e. when you have occasion to manifest by your practice which you prefer — when you must either cleave to one or the other, and must either forsake other things, or forsake God — whether then it be your manner practically to prefer God to all other things whatever, even to those earthly things to which your hearts are most wedded. "He who sincerely prefers God to all other things in his heart, will do it in his practice. ...Therefore there is no sign of sincerity so much insisted on in the Bible as this, that we deny ourselves, sell all, forsake the world, take up the cross, and follow Christ whithersoever he goeth."