God IS Omnicient ~ He knows all things ~ He knows you, and me ~ He knows the hearts of the sinners and the Christians. Even if one has accepted Jesus Christ into their hearts, to be their Lord and Savior, He still searches into the depths of our hearts. Nothing can ever be hidden from His eyes.

If we have forgotten the Name of our God, or stretched out our hands to a strange god;
shall not God search this out? for He knoweth the secrets of the heart.
 ~Psalm 44:20-21

Being a Christian doesn't mean that we become immediately perfect. We still have sinful hearts, and walk in flesh that cries out for carnal pleasures. Yet, if we believe in the Name of the Lord Jesus, and trust Him and all that He says in His Word, He knows that too. By His saving grace, His shelters those that trust in Him.

The LORD IS good, a stronghold in the day of trouble; and He knoweth them that trust in Him.
~ Nahum 1:7

Being a Christian means that we Love the Lord, we depart from sin, and walk with Him. This shows our devotion to Him, that we trust in His Name, and that we Love Him. In His strenth, we can stand.

Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are His. And, let every one that nameth the Name of Christ depart from iniquity.
~ II Timothy 2:19

Again, the Lord knows our hearts ~ only He does. He weighs our hearts. Do we have Love for Him, and for one another, as He has instructed us? The Lord knows.

For if our heart condemn us, God IS greater than our heart, and knoweth all things.
Beloved, if our heart condemn us not, then have we confidence toward God.
And whatsoever we ask, we receive of Him, because we keep His commandments, and do those things that are pleasing in His sight.
And this IS His commandment, That we should believe on the Name of His Son Jesus Christ, and Love one another, as He gave us commandment.
~ I John 3:21-23

Lord Jesus,
as You look into my heart, I pray that You Will wash me clean of all my wicked intentions and desires. Equip me with Your Love, O God, so that I can Love others in Your Holy Name, as You have given me command to do. Thank You for Loving me first and for ever, my God and my King. Amen.