Just pondered on this issue and concluded it is indeed a sin and I have decided to stop/prevent it.

Reasons

1. It is a sin to kill yourself

2. It is a sin to defile your body - fornication, adultery, masturbation etc

The above are sins one commits against their own body.

Hence, it is equally a sin to lie to yourself.

What do you think?

write2obi: @Op how exactly can someone, lie to him/her self?

lol

E.gs 1. When you see someone you don't like to see or you are not happy with and smile at the person.

2. When you call someone to come and eat and you don't mean it

etc etc etc

write2obi:
Oh! That!, I don't see those as sin

Really?

Do you ever feel ok after lying to yourself or do you suffer guilty conscience?

Also, there is a tendency for it to lead to another sin.