If your fundamental is a man dying on the cross for his enemies, if the very heart of your self-image and your religion is a man praying for his enemies as he died for them, sacrificing for them, loving them - if that sinks into your heart of hearts, it's going to produce the kind of life that the early Christians produced. The most inclusive possible life out of the most exclusive possible claim - and that is this is the truth. But what is the truth? The truth is a God become weak, loving and dying for the people who opposed him, dying forgiving them.
The early church was strikingly different from the culture around it in this way - the pagan society was stingy with its money and promiscuous with its body. A pagan gave nobody their money and practically gave everybody their body. And the Christians came along and gave practically nobody their body and they gave practically everybody their money.
Everyone will be forgotten, nothing we do will make any difference, and all good endeavours, even the best, will come to naught. Unless there is God. If the God of the Bible exists, and there is a True Reality beneath and behind this one, and this life is not the only life, then every good endeavour, even the simplest ones, pursued in response to God's calling, can matter forever.