"Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water." (Hebrews 10: 22)
We can come to God knowing that He will never punish us, nor hold our sins against us:
"Therefore, there is now no condemnation for those who are in Christ Jesus," (Romans 8: 1, NIV)
John tells us that we do not have to worry about what's on our hearts, in the first place:
"And hereby we know that we are of the truth, and shall assure our hearts before him." (1 John 3: 19)
Let us always remember that the truth is a person (John 14: 6), and the truth speaks of the Gospel of Grace.
Grace and truth are one in Christ:
"For the law was given by Moses, but grace and truth came by Jesus Christ." (John 1: 17)
The truth of grace, not the law, sets us free:
"31Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed; 32And ye shall know the truth, and the truth shall make you free." (John 8: 31-32)
The truth is all about the Gospel:
"To whom we gave place by subjection, no, not for an hour; that the truth of the gospel might continue with you." (Galatians 2: 5)
And the Gospel in short form is provided for you here:
"Be it known unto you therefore, men and brethren, that through this man is preached unto you the forgiveness of sins: 39And by him all that believe are justified from all things, from which ye could not be justified by the law of Moses." (Acts 13: 38-39)
But what if our heart is not assured?
20For if our heart condemn us, God is greater than our heart, and knoweth all things" (1 John 3: 20)
We need to know that God knows everything about us, yet He sent His own Son to die for us (John 3: 16), and that He remembers our sins no more (Hebrews 8: 12)
21Beloved, if our heart condemn us not, then have we confidence toward God. 22And whatsoever we ask, we receive of him, because we keep his commandments, and do those things that are pleasing in his sight."
We have this confidence, that all things have been taken care of, and that we are fully washed and sanctified in Christ.