My defense is of God which saves the upright In heart. I am glad that God looks on the heart of man. God knows our hearts, he knows if there has ever been a time when we, from our hearts, have cried out to him in sorrowful repentance of our sins and believed on the Lord Jesus Christ and received him into our hearts as Lord and Savior. We can judge no man, for we cannot know what is deep in the heart of any man, only God can know that; but if we believe that our own heart is right with God, then we can rightly say that our defense is of God, and knowing that God's word is sure and steadfast we can agree wtih God that he is angry at the wicked every day.
We ought to be good evangelists and sound forth the warning that all may hear what God has proclaimed to all - “That God judgeth the righteous, and God is angry with the wicked every day. If he turn not, he will whet his sword; he hath bent his bow, and made it ready. He hath also prepared for him the instruments of death; he ordaineth his arrows against the persecutors.” Psalm 7: 11-13..
The arrows of God's judgment, aimed at the wicked, are already set and under the pressure of a bent bow. Only God's mercy and long suffering prevents the release of God's arrows of judgment.
God is merciful and kind, not willing to pour out wrath, but to bathe us in love. We all ought to examine our own heart very carefully to see if we are among the wicked in heart, or if our hearts are right toward God so that we may say, my defense is of God.