Luke 1:17 English Standard Version (ESV) and he will go before him in the spirit and power of Elijah, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just, to make ready for the Lord a people prepared.”
1 Corinthians 2:9 English Standard Version (ESV) But, as it is written, “What no eye has seen, nor ear heard, nor the heart of man imagined, what God has prepared for those who love him”
According to Ezekiel 36:26 we have been given a new heart and a new spirit. That new heart knows nothing about how to love as God loves. The new spirit is given to teach that heart how to love.
The issue of preparing the heart has to be seen in the light of this truth, it is being prepared for the Lord. We have not yet come to the wedding feast. Our hearts are being prepared for that day.
Revelation 21:2 calls us “prepared as adorned for Christ”.
We are human, we have not been translated yet and as such we are still undergoing preparations.
What we might fail to understand is that this new heart is His heart, after all He is Lord. As such He will love us in a way that will not damage our hearts. He will do nothing to scare us off and seeks only to draw us closer to Him.
Ephesians 3:19-21 English Standard Version
19 and to know the love of Christ that surpasses knowledge, that you may be filled with all the fullness of God. 20 Now to him who is able to do far more abundantly than all that we ask or think, according to the power at work within us, 21 to him be glory in the church and in Christ Jesus throughout all generations, forever and ever. Amen.
“At work within us.” Preparing us.