oh you know what disregard my previous post. i didn't really look into detail on what you were meaning. i thought you had a hard relationship and you had trouble with her as non believer. but since you are the non believer i will have to reword my previous posts.
since she is the christian believer and your the non believer. she is the one that opened her arms to you. which i hope was the right reason spiritually as she saw that you are lost and you need help getting on the path of righteousness.
i wouldn't say you are messing her life up but your certainly helping her reach to you to help you have a better or strong relationship with christ.
one thing since i see you are atheist i'm not pressuring you and i'm sure she isn't either. but i would suggest you go to church with her and go up for prayer when the pastor asks does anyone need prayer. i suggest you at that time ask jesus for forgiveness of your sins and to start a new clean chapter in your life because its never to late to accept jesus. he is there opening his arms as we speak and he is just waiting for you to accept him.
unlike this world you have to be a certain way to fit in.
i didn't mean to say she is carrying the flies but you are right you are carrying the flees in this situation and its in your best interest to burn those flees and cast them away.
as peter said to the men in the book of Acts 2: 38 "then peter said to them, 'repent, and let everyone of you be baptized in the name of jesus christ for the remission of sins; and you shall receive the gift of the holy spirit."
and jesus was put in the same situation as you but he said it rigorously to satan and you should do the same as jesus put an example to us in the book of matthew 4: 10-11 "10 then jesus said to him, 'away with you, satan! for it is written, you shall worship the lord your god, and him only you shall serve.'" 11 "then the devil left him, and behold, angels came and ministered to him."
take those verses to heart my soon to be brother in christ. i pray your girlfriend ministers to you as some in this thread has to you.
now everything is in your hands whether you choose to go the path of christ or to go the lost path. your decision...
may my post be a blessing to you and god bless
