Love is the foundation of Christianity. God so loved the world that he gave us his only begotten son. God commanded his love towards us while we were still sinners. Sinners receive grace to turn into children of God motivated by His desires.
But when a person is born again the grace of God has been shed abroad in their heart. This love is greater than any we have ever known and the purpose of giving this gift to us is so that we can share it with everyone we meet. God uses His people to spread His message to the world at large.
People who do not share these same feelings tend to offer conditional love to everyone they meet. This means that if they are in a relationship with someone else they promise to be there for that person as long as that person remains the same. When all is going well mutual feelings of affection abounds But let one person do something the other does not approve of and suddenly those feelings of affection are gone. It disappears.
How can someone tell if they are walking in conditional or unconditional love? How is it possible to know for sure that unconditional love remains unconditional? It has to do with understanding how this type of love works. Conditional love focuses on the actions of others to determine whether or not to extend love. If their actions are pleasing then love is given. But whenever those actions change (and they always will when it comes to dealing with people) so too will the feelings between the two. Many people have thought they were in love only to find out that a single incident could erase that love forever.
Unconditional love focuses solely on the belief of the person who is expected to extend love to others. It does not pay attention to what others think or say. It is based solely on a decision to love. God does not love us because we do things right or hate us because we sin. He loves us because He makes the decision to love us. Our actions do not cause Him to love us more or less. His love is based on His decision not ours.
To love others in the same way boils down to making a decision to do so. Unconditional love will not operate unless it is powered by a will determined to love regardless. It moves actions to a place where sin can be forgiven.