The missing piece may be that there is something that occurs in between enmity with God and that moment a person opens his heart to truth. God says he is a rewarder of those that diligently seek him. When I asked the Lord for the truth, and he knew in my heart I was sincere, he revealed the gospel to me and I recognized it. Did God give me the ability to "see" the truth when I heard it? Yes. But, by no way glorifying myself, I had to be open to hear it.
From a personal point of view I would like you to think about this before you respond and tell me, before you came to Christ, did you seek God, or did God first seek you?
For me, I was dragged kicking and screaming to the Cross of Christ. Hence the words from the song by Third Day ring true for me:
Who is this King of Glory That pursues me with his love And haunts me with each hearing Of His softly spoken words My conscience, a reminder Of forgiveness that I need Who is this King of Glory Who offers it to me
As I look back on my salvation experience, I can say with assurance that I was not seeking after God, but He was pursuing me and eventually dragged me kicking and screaming to the cross. Left to my own "choices" I would never have chosen Christ. Does that mean I am a Calvinist? No, it does not. Does that mean I understand the Calvinist concept? You bet it does. I am a product of exactly what they preach; a God who pursues men and who soverignly violates their free will at every turn until they come face to face with God's "irresistible grace".
I don't know why God would pursue me with his Love, but He did. Although I accept that ultimately my "free will choice" was to "Choose Christ", it was not until my own free will had been sufficiently destroyed by God's intervention that I was made capable of making that choice. At that point it was irresistible. I was in a corner from which the only exit was through the cross of Christ. God put me in that corner.
If your heart could do this good thing of sincerity prior to its being regenerated, then your heart was not "deceitful above all things and desperately wicked..."
Why was your heart not deceitful above all things and others have hearts that were deceitful above all things?
And why does the Bible proclaim a sinful heart to be the birthright of all humanity, for it clearly says that "no good thing resides in me."