Chiming in, responding to the title of the OP.
Yes unbelievers can be considerate, thoughtful, merciful and kind. I believe God can use said traits to bring them to Him, to bring others to Him. I think it a blessing, but still believe they need, MUST, to come to Christ.
With that said...
If we follow Him, how can we not exhibit love. He is Love, and I do not speak of merely the emotional ooey gooey stuff, though He provides a steady supply of that too, for Him and others. We see in His example and His word what love looks like.
It is filled with mercy, service, care, humility, selflessness, investment, endurance, patience, kindness, hospitality, truth, and sacrifice. We are called to pay Him forward, in what we say, think, and do. Yes, He even says that we can be identified as His by loving others. Sometimes love doesn't always come with sweetness, sometimes we face resistance and admonishment, but even then it should be served on a plate of grace, dignity and consideration. Otherwise, the receiving of it can be lost in the translation.
Lord, great almighty, ruler of all...please, help us all love as we are called. We are so thankful that Your grace abounds so that ours can. We are hopeful to grow in love as we grow in You.