Loved With Everlasting Love

The Lord hath appeared of old unto me, saying, Yea, I have loved thee with an everlasting love: therefore with lovingkindness have I drawn thee (Jer. 31:3).
Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others (Eph. 2:3).

The question asked is: "Is God both loving and angry with a Christian at the same time before his conversion?"
The problem which the questioner raises is rooted in a very common misconception. That misconception is: Anger is incompatible with love. But is this really true? Let us think about it for a moment. Even in human relationships it is possible to be angry with a friend, while one's love for the friend remains constant. Perhaps the friend has done something cruel and we are justly angry at this unexpected act of cruelty. The same is true of the relationship between parents and children. Parents, especially covenant parents, love their children dearly. But does this love exclude anger when the children are disobedient? By no means.  So also in God's relationship to His people. He can both love them and be angry with them at the same time. We may even carry this one step further. God is angry with them because He loves them.
We must look at the matter a little more closely, howevcr, so that we understand it well, for it touches on an important aspect of our own life of fellowship with God.
God loves His people with an eternal love. This is the clear and unmistakable language of Jeremiah 31:3, which text the reader included with the question.

 This eternal love which God has for His people is not, however, in any way rooted in them or based upon them. These people have not only not done one thing to merit that love; they have done everything to make themselves unworthy of that love, for they have sinned in Adam and their sinful flesh always brings forth evil works.
God's love is rooted in His own divine being. He loves Himself with a perfect love as the triune God. He sovereignly and freely chooses to reveal that love in such a way that He loves wholly unworthy sinners whom He makes the object of that love. Those whom He makes the objects of His love are those whom He chooses to be His own elect people.
These elect people are, by nature and through birth, utterly depraved. God cannot and does not love them as sinners; this would be impossible. He loves them in Jesus Christ, His own Son, whom He gave to make the perfect sacrifice for sin that only God's Son could make. "Herein is love, nor that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins" (I John 4:10).
This eternal love of God does not mean that God can never be angry with His people. He is angry ... frequently. He is angry with them when they are as yet unconverted. He is angry with them when they turn their backs on His law and walk in their own ways; when they are ungrateful for all His blessings; when they despise the good things He gives to them.
But this anger of God is shown to them so that it is their experience. While they are unconverted, they know only the anger and wrath of God. But it is equally their experience when, after they have been converted, they turn to sinful ways and will not confess their sins. (Read Psalm 32.)
But anger is not incompatible with love. God causes His people to experience His anger in order to restore them and lead them back to Himself. Knowing His anger, they cry out in sorrow for sin and seek forgiveness in God's mercy. Any child who loves his parents does the same. He cannot bear to have his parents angry with him; thus anger becomes a means to bring him to repentance.
Especially when God chastises us do we experience His anger upon us. This explains why the Psalmist cries out, "O Lord, rebuke me not in thine anger, neither chasten me in thy hot displeasure" (Ps. 6:1). Remember, this is a converted David who prays this.
But it is quite different with the wicked. God is angry with them too, of course. But God's anger is nor the correcting anger of love, but the destroying anger of hatred and the curse. God loved Jacob, but He hated Esau (Rom 9:13). Upon Esau He poured out His fierce anger. This too is rooted in God's own being: His love for Himself as the only true and holy God; His hatred of sin; His fierce avenging fury against the workers of iniquity.
It is because God's wrath is poured out upon His Son that the believer runs with speed to the cross to hide beneath its shadow. The cross is the pre-eminent display of how God deals with us. The cross is the awful suffering that it was for Christ because all the fury of God's wrath for the sin of all the elect was poured out on Christ. It was the full wrath of God as revealed in Hell. It came upon Christ in such full measure that He knew nothing but wrath, and was so swallowed up in it that He momentarily could not understand why this awful maelstrom of fury should engulf Him: "My God, my God, why... ?" And yet at that moment when Christ knew only God's anger, God, as it were, loved Him the most. For Christ, even in that black hour, loved His God with all His heart and mind and soul and strength. Christ, even at the bottom of Hell said: "I cannot understand such awful agony, nor why Thou art angry with me; but, oh my God, I love Thee still." How is it possible that God could have anything else but love for His own dear Son? -- even when Christ knew nothing but wrath? It was the display of God's love for Himself revealed in love for sinners such as you and I.
Every child of God knows something of God's anger. Let us not conclude from this anger that God no longer loves us or that we are not one of His children; let us repent of our sins, forsake our evil ways, and flee to the cross for refuge. There we will find the love of God in all its amazing blessedness.