I'm reading a Gospel Primer for Christian by Milton Vincent. I am about half way through the short book and I'd commend it to you for your personal meditation and growth. Here are couple of exerts about the effect of the gospel in growing my love for Christians.
"The more I experience the gospel, the more there develops within me a yearning affection for my fellow-Christians who are also participating in the glories of the gospel. This affection for them comes loaded with confidence in their continued spiritual growth and ultimate glorification, and it becomes my pleasure to express to them this loving confidence regarding the ongoing work of God in their lives.
Additionally, with the gospel proving itself to be such a boon in my life, I realize that the greatest gift I can give to my fellow-Christians is the gospel itself. Indeed, I love my fellow-Christians not simply because of the gospel, but I love them best when I am loving them with the gospel. And I do this not merely by speaking gospel words to them, but also by living before them and generously relating to them in a gospel manner. Imparting my life to them in this way, I thereby contribute to their experience of the power, the Spirit, and the full assurance of the gospel.
By preaching the gospel to myself each day, I nurture the bond that unites me with my brothers and sisters for whom Christ died, and I also keep myself well-versed in the raw materials with which I may actively love them in Christ." (pp.22-23)
The gospel shapes the way I look at the church:
"Hence, the more I comprehend the full scope of the gospel, the more I value the church for which Christ died, the more I value the role that I play in the lives of my fellow-Christians, and the more I appreciate the role that they must be allowed to play in mine." (p.24)
The gospel shapes relationships and my forgiveness of others:
"When my mind is fixed on the gospel, I have ample stimulation to show God's love to other people. For I am always willing to show love to others when I am freely mindful of the love that God has shown men. Also, the gospel gives me the wherewithal to give forgiving grace to those who have wronged me, for it reminds me daily of the forgiving grace that God is showing me.
Doing good and showing love to those who have wronged me is always the opposite of what my sinful flesh wants me to do. Nonetheless, when I remind myself of my sins against God and of His forgiving and generous grace toward me, I give the gospel an opportunity to reshape my perspective and to put me in a frame of mind wherein I actually desire to give this same grace to those who have wronged me." (pp.24-25)
This of course echoes Jesus' parable in Matthew 18 of the servant who is forgiven a great debt but is unable to forgive the debt owed him. When we grasp the free forgiveness of the gospel, we in turn are willing to freely forgive and show sacrificial love. Many times what keeps us from forgiving others is pride. We rationalize: "We have been wronged," we demand that we are owed justice and fair reparation, or equal treatment to set the scales right. And yet, in God's forgiveness of us, he absorbs the cost of that forgiveness by sending the Son to pay for sin.
When a Christian forgives, it is costly in a different sense. It is cost because it forces us to be humble enough to be willing to forgive. It entails forgoing our right or the justice we deserve and showing mercy and love. It entails serving the other person and not considering ourselves better than them because we were in the right and they were wrong. Love is profoundly sacrificial and that's why it takes the gospel to "get it" and show true love to others.