I John 4:11-12 Dear friends, since God loved us that much, we surely ought to love each other. God lives in us, and his love has been brought to full expression through us.
It is unnatural for God's children to not act in love. Loving others should be as natural to us as breathing and eating. God is love and when He lives in us, we take on His nature. The thing that stands in our way is sin. We are born sinners. We are born with an inclination and desire to sin. Without Christ in us we have no help to keep us from sinning. We act and react in sinful ways. When we are in Christ, He helps us to change from being sinful in nature to godly in nature. There should be a progressive change in our nature. We should become like Him in His holy love.
It should be our desire to be a people of godly love. We should want to treat others lovingly. We should want to be helpful and encouraging to others. We should want to set aside our differences and have fellowship with others. We should want others to be blessed and enjoy a good life.
When we can't love others, especially those in the faith, we have a heart issue with God. The Lord can, and longs to, help us, but we must be willing to let Him. He will give us loving hearts if we ask Him to. He will replace our hearts of stone with hearts of love, if we ask Him.
If you have a hard time loving someone, let the Lord change you. It may not happen overnight, but He will help you if you sincerely ask Him to. The more you pray for a change of heart, the more change you will see in your heart. It is God's desire for you to change. He wants to fully express His love for others through you. Will you let Him?