Hebrews 8:10-12 (ESV)
For this is the covenant that I will make with the house of Israel
after those days, declares the Lord:
I will put my laws into their minds,
and write them on their hearts,
and I will be their God,
and they shall be my people.
 And they shall not teach, each one his neighbor
and each one his brother, saying, 'Know the Lord,'
for they shall all know me,
from the least of them to the greatest.
 For I will be merciful toward their iniquities,
and I will remember their sins no more."
“For I will be merciful toward their iniquities, and I will remember their sins no more.” God says we will all know Him. The least to the greatest. And the reason he gives for us knowing him, will be simply because he will be merciful to us. The Gospel, the gospel teaches us to know God. Forgiveness, Mercy, these are the sources of knowledge in God. We know God, only because of his mercy toward us. His law would drive us away from Him, if we did not also know of Christ who died for us.