I do almost all that stuff; play games, watch secular movies/TV/music, drink caffeine, speak idle words, have foolish thoughts, etc. I'm saved and eternally secure. I don't lift a finger to "retain" my salvation.
You'll drive yourself nuts trying to do all those pennants, plus you'll never succeed. The more pennants you complete the more pennants you'll discover that you haven't done yet. It never ends. It's the devil's little trick - there's no grace there.
If you are trusting the Lord Jesus Christ as your Savior then you're "in Christ Jesus". Walk not after the flesh but after the Spirit; not to avoid the condemnation of hell but to avoid the condemnation that is described in the previous verses in chapter 7.
Walking after the Spirit will help you succeed in your daily practical sanctification. It will make you happy with the joy of the Lord. When you sin, confess it in order to restore fellowship with God (not to retain salvation). I have days when I sin/confess, sin/confess, sin/confess. Putting off the old man and putting on the new man can be quite a battle. But my eternal salvation is never at stake.
The very verse you quote refutes you. Let's read Romans 8:1 in what it says.
1 "There is therefore now no condemnation to them who are in Christ Jesus, who walk not after the flesh, but after the Spirit."
(Romans 8:1).
Are you walking after the flesh or are you walking after the Spirit?
According to Romans 8:1, there is no Condemnation to those who walk after the Spirit.
If you sin, and walk after the flesh, you are under the Condemnation.
If you do not sin and walk after the Spirit, you are not under the Condemnation.
Most Eternal Security Proponents believe that you are not under any kind of Law.
Most of them also believe they are not fulfilling any righteousness of the Law, too.
But that is not what the Scriptures say.
4 "That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
5 For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit."
Stop right here.
They that are after the flesh do mind the things of the flesh. You said you sin all the time and do sinful things. Are you walking after the Spirit when you sin? Is there an option here in Romans 8 by Paul that says you can walk after the flesh and also after the Spirit?
Anyways, lets keep reading.
6 "For to be carnally minded is death; but to be spiritually minded is life and peace."
(Romans 8:6).
Did you catch that?
To be carnally minded is death.
This would be spiritual death because most everybody physically dies.
In fact, the Lake of Fire is called, the "Second Death." (Which is a reference to "spiritual death").
Okay, let's continue to keep reading.
7 "Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
8 So then they that are in the flesh cannot please God."
(Romans 8:7-8).
The above passage here says they that are in the flesh cannot please God.
So no. You cannot be in the flesh and please God. Those who do not please God will not be in Heaven. To say so otherwise would be a contradiction in terms.
Romans 8 does not give you the option of walking after both the flesh and the Spirit.
Jesus says you cannot serve two masters, for you will hate the one and love the other (Matthew 6:24).
Scriptures says we are to work out our salvation with fear and trembling (Philippians 2:12).
...