So how do we "let love be without hypocrisy" (Romans 12:9)? God Himself is kind to the unthankful and evil (See Luke 6:35), and such a love can only come through Him if we are to “be merciful just as [our] Father also is merciful” (Luke 6:36). If it is done in the flesh, then it can only be self-love. Here is how Dave Hunt explained it in his April 2007 newsletter:

The man who persuades a woman to live with him without marriage tells her, “I love you.” But what he may mean (perhaps unknown even to him) could be, “I love myself, and I want you”. Only too late they may discover that this is what both of them mean by “love”. (Dave Hunt, from his newsletter titled Why Everything Is The Way It Is)

Any fleshly attempt at love will be a vain attempt. And if my love truly has come from Christ, then I have no reason to be thinking, “Oh, what a wonderful loving person I am”. If I am in that state of mind, and focusing on how great I am rather than how great God is, then I may be easily offended when someone does not see me as a loving person. My focus will be more on self defense rather than caring about what people think of God and His love. In this case of self defense, my thoughts may be something like “how dare that person not see the love that I have for him! I am full of Christ's love!” The love in that case is obviously not for the other person, but for self.

On the other hand, true love for God and others will have no burdens about self, but many about others. It will truly understand that it is a love which comes through God, and not from the flesh. It will love Him because He first loved us (See 1 John 4:19). Only this love flowing from His heart can love without hypocrisy. Here is another quote to help explain what I am getting at:

“A new commandment I give unto you, that ye love one another; even as I have loved you....” (John 13:34).

“Even as I have loved you...” is the command of Him who asks nothing that He has not provided, and now offers to bestow. It is the assurance that He expects nothing from us, that He does not work in us. “Even as I have loved you and every moment am pouring out that love upon you through the Holy Spirit, EVEN SO do ye love one another”. The measure, the strength, and the work of your love you will find in Christ's love to you. (Andrew Murray, Like Christ, 1895, p. 127)

As I explained in my article titled What Is Humility, Jesus Himself becomes our humility.