If Christianity is true, then how should that affect us in our every day life?

It should transform everyday life into a type of heaven on earth. The most significant example of that transformation is to be found in the Christian family and then, the various, authentically Christian, religious orders. Due to today's rampant secularism and materialism, things tend to break down fairly quickly, after that. But such was not always the case.  

" If Christianity is true," ...... it aint true.... So mute question unless you can prove otherwise........And you cant eh

That's "everyday" life, not 'every day life', so step one should be to learn how to write in your own native language. Fortunately however, Christianity is no more true than any other religion, so you really don't have to worry about it. Just be a good person, do things that help people instead of harming them, and everything else will work itself out. 

Love God.  Love your neighbor as you love yourself.  Love your enemies.  Do right, be kind, and walk humbly with God.  Treat other people as you would have them treat you. 

REMEMBER TO LOVE ONE ANOTHER...GOD SAID THAT.

It shouldn't if you're living right.