1)  “Everything happens for a reason.”
Explain that one to a young teen who was molested by her uncle.  God hates incest.  Abhors it.  It didn’t happen for a reason.  Rom 8:28 isn’t about his causing things to happen but to redeem things that do happen (“He causes all things to work for the good for those who love Him–8:28).  He brings good out of good things and brings good out of bad things.

2)  “Everything in Moderation”
Everything?  Not at all.   There is no moderation for sin–a little lust, a little greed, a little adultery, a little murder, a little porn.  There is no moderation in righteousness either–A little love, a little joy, a little peace, a little generosity, a little kindness.

When someone says all things in moderation, they are usually referring to sin in excess.  But sin is sin.   And yes, there are some things permissible in moderation–alcohol consumption, food cosumption, etc…

But all things?  Not.  At.  All.

3)  “It doesn’t matter what you believe as long as you’re sincere.” 
Then Jesus’ death meant nothing.

4)  “All religions are the same, it’s about doing good.”
Almost.  Almost all religions are the same.  A whopping 99.99% of religions are about earning God’s favor.  Except Jesus.  Jesus says you can’t earn the Father’s favor.  But he’ll die and pay the price/ consequences of your conduct.  Therefore you now live not for his favor, but from it.

5)  “As long as you’re a good person, that’s what matters.”
Jesus didn’t die for good people.  He died for sinners.  If the above is true, again, Jesus did not need to die.