It does not come naturally.
Love is a decision. Forgiveness is an intentional act of the will even when we don't feel it. There is nothing automatic regarding our growth in the Lord. A.W. Tozer wrote: "The ethics of Jesus cannot be obeyed or even understood until the life of God has come to the heart of man or woman in the miracle of new birth."
But once our hearts are filled with Him we can walk out the righteousness of God within us. But just like we have to cleanse ourselves physically each morning and then put on fresh clothes – we must put on mercy, kindness, humility, love, forgiveness and patience. On this fiftieth day of blessing – let's put on Christ Jesus.
"Therefore, as the elect of God, holy and beloved, put on tender mercies, kindness, humility, meekness, longsuffering;"Colossians 3:12 NKJV