A huge amount of misinformation about agape has infiltrated the common culture of well meaning disciples. Here is an example:
When we realize that he [meaning the Apostle Paul] never uses the word agape to express man’s love to God, we shall not think that it is of man’s love that Paul speaks in this verse. Agape, the love which God showed us in Christ, is for Paul so tremendous a fact that he regularly refrains from using the same word to express our love to God. 
This quote is from the primary teacher about agape, Bishop Anders Nygren, in his commentary on Romans. It is cited by Kent Hughes as part of his interaction with Romans 5:5-8.
Dr. Hughes is a godly, well-informed, thoughtful and effective expositor. He has mined the work of responsible scholars and, together with his own conclusions, provided the minister or serious student with easily accessible commentaries on the Scriptures. They are a delight to read and are a treasury of valuable insights. Bishop Nygren was the extraordinarily influential primary proponent of the view that agape is inaccessible, volitional, non-emotional, sublime.
The concept conveyed in this citation adds to the confusion of the nature of agape and is easily exposed as being unfounded. In fact, a brief use of an accurate Bible program will reveal three uses of agape by Paul as it relates to believers loving God or God-Incarnate-Glorified, Jesus.
And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. (Romans 8:28)
but if anyone loves God, he is known by Him. (1 Corinthians 8:3)
Grace be with all those who love our Lord Jesus the Messiah with incorruptible love. (Ephesians 6:24)
These verses say the following: For those who agape God all things will work together for good. Those who agape God are personally known by God. The apostle released grace to those who agape Jesus. None of these statements are without import.
Not only does Paul write that the Lord is to be agaped, but so also is His appearing. A reward, “the crown of righteousness” will be presented to those “who have loved His appearing”.
in the future there is laid up for me the crown of righteousness, which the Lord, the righteous Judge, will award to me on that day; and not only to me, but also to all who have loved (agape) His appearing. (2 Timothy 4:8)
Agape in this verse is translated “longing” in the New International Version and New Revised Standard Version. The New English Translation translates it with a different emphasis that reveals another acceptable nuance of agape within this context:
… and not to me only, but also to all who have set their affection on his appearing. (2 Timothy 4:8b)
The thought that agape is so sublime as to be out of reach of mere mortals is an unfortunate mistake. In fact, what is being excellently communicated is unfortunately inaccurate. It is ludicrous to say Paul’s view of agape is so high and exalted that the apostle cannot lawfully employ agape to describe the love which regenerated, Spirit-filled believers have for God. This idea further mystifies this essential and foundational emotion. The resultant confusion makes it more difficult for us to relate to the love God has for us in, and with, the Messiah.
In our example from Ephesians 6:23-24 we find that our love for the Messiah is a reciprocal love. The initiator of this love is the Father and the Son. The recipients are those who respond to God in the Messiah.
Peace be to the brethren, and love with faith, from God the Father and the Lord Jesus the Messiah. Grace be with all those who love our Lord Jesus the Messiah with incorruptible love. (Ephesians 6:23-24)
Speaking of God-Incarnate-Glorified, didn’t He have something to say about loving God? Before He was resurrected and glorified, Jesus reinforced the ancient command to agape God.
Not only is it possible for humanity’s love for God to be described as agape, we are commanded to love (agape) God. This is a love which motivates the heart, thoughts, volition and use of talent and resources.
And He said to him, “‘YOU SHALL AGAPE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND.’ “This is the great and foremost commandment. “The second is like it, ‘YOU SHALL AGAPE YOUR NEIGHBOR AS YOURSELF.’ “On these two commandments depend the whole Law and the Prophets.” (Matthew 22:37-40)
God agapes sinners and those He has redeemed. Let us reciprocate.
 Ander Nygren, Commentary on Romans (Philadelphia Fortress Press 1978), p. 183
 Kent Hughes, Romans, A Righteousness From Heaven, (Wheaton, Illinois, Crossway Books, 1991), p. 109