There are many signs over whether we are losing the duel with the devil that may be easily ignored, or readily apparent. This list has no real order and is more something to think about.
For a short period of time some flaws and issues may seem normal and not destructive but eventually if left unchecked the only people we hurt are ourselves and those around us.
Not trying to improve
As Muslims every day we should strive to be better than we were yesterday. If we are not doing this, at best it is a score draw, but more likely a sign of losing.
This is a big one. No one is perfect, but we should try to hide our sins and feel bad about them. If this changes to where we no longer try to hide them and don't feel bad, we have already lost.
gaining bad habits
Not trying to give up bad habits.
I guess this fits into "Not trying to improve"
Thinking we "deserve better"
The idea that we have a right to get better from the world will only result in anger and frustration because we get what we get, not what we think we deserve.
It is also easy to forget how much harder life could be. The other day I was watching a documentary on the only train in Nepal on BBC4 and how a mother was surviving and providing for her family by crossing the border into india to smuggle goods for the shops.
These people were very poor, but even the songs they sang were grateful "I wanted a dress and God gave me two..."
Avoiding company of better people
Humans are communal and the company we keep influences us. So keeping the company of better people has a better chance of improving us than those that are not better.
Thinking we are better than others due to family, wealth, status or even religious action. Our standing in the eyes of the Lord may not be as high as the esteem we hold ourselves in, and others may be far nobler in the eyes of God than we consider them to be.
Now after all the flaws and sins, despair at being doomed is one of the worst - while God is just, He is also merciful and no matter how bad our sins are, if we turn to God, repent and do good deeds, we can avoid God's wrath - We can never thing that our sins are greater than the mercy of God.
Having a large deficit between our character and reputation
When our character does not meet the standards expected by our reputations, the day that people encounter the true us may be a bad day indeed as suddenly the veil of reputation would be lifted.
We need to understand that not everyone can be like us, and while they may sin secretly or openly, they have their own struggles and may be nobler in the sight of God than us.
Why change now when we can when we are older? Yeah, everyone knows what will happen there.
"Everybody does it"
That is a bad justification to do something.