“Which is harder, to have faith or to live your own life without God?”

A Christian must die to self.
Romans 6:2-4
"...We died to sin; how can we live in it any longer? Or don’t you know that all of us who were baptised into Christ Jesus were baptised into his death? We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may have a new life."

St Paul struggled with sin:
Romans 7:14
"... We know that the law is spiritual; but I am unspiritual, sold as a slave to sin. v 18 For I have the desire to do what is good, but I cannot carry it out. For what I do is not the good I want to do; no, the evil I do not want to do - this I keep on doing."

Romans 14:23
"...and everything that does not come from faith is sin."