As a Christian, after sining have you ever been deceived by satan by thinking that you failed again, aren’t good enough and that God gave up on you?
I have and it’s remembering the message of the gospel that put an end to satan deceiving because Jesus has redeemed me and declared me righteous.
To me belief in the power of the gospel is the great chain that bound satan by deceiving me.
I don't really want to go into the following depth because of what you said, but I feel I must, because once we have believed on The Father and His Son's death and resurrection, and been baptized, our work as one of His disciples has actually just begun.
In Hebrews 5, Apostle Paul kind of got onto the brethren because of their staying on the 'milk' of salvation principles instead of becoming teachers on the "strong meat" of The Word. Once one believes on Jesus Christ they are to get into and stay in His Word to become one of His disciples (John 8:31-32).
Nothing wrong with feeling joy, peace, and the feeling of having been saved in Jesus Christ, but there's much more work to do than continually dwelling on those feelings (not saying you are doing that, I'm just giving examples). Coming to Christ doesn't mean throwing a party, it means getting down to His Work per His commandments.
And by staying in God's Word, that is one of the most powerful ways to not be deceived by the devil. So can the devil still deceive a believer on Christ Jesus? Yes, if they allow it. How's that? (and this is the hard part I'm going into).
Per Apostle Paul's Epistles, we see where he was continually warning brethren against following and doing evil, and even how some brethren had interpreted liberty in Christ Jesus meaning being allowed to do many things which God's Word is against. So Paul actually rebuked brethren quite a bit for sinning in His Epistles. In 1 Timothy 1, 1 Corinthians 6, and Galatians 5, Paul even pointed to the breaking of God's law as what it means to walk by our flesh, instead of by The Spirit. Many brethren were then still walking by their flesh, even while they believed on Jesus Christ, just as it still is for today with many brethren.
How then, could those brethren be seen as being 'in Christ' while following their flesh? In Acts 20:26-31 Paul even said in the future after he left, wolves would creep in among the brethren and turn some away, and even among themselves some would turn to speaking perverse things and draw followers after them. So Paul said for three years he did not cease from warning them night and day with tears.
So once a believer has come to Faith on Jesus Christ, what did Apostle Paul show about Satan still being able to deceive them?
One of the main ways for a Christian brother/sister to still be deceived by Satan is by NOT staying in God's Word. Just by the examples that Apostle Paul gave us in His Epistles the new babe in Christ ought to quickly come to knowledge about. But if one doesn't discipline theirselves in God's Word, they won't understand that point, and will more easily become deceived.
"Well, as a Christian, I am promised The Holy Spirit, so there's no need for me do a lot of Bible study, The Holy Spirit will guide me," which the latter part of that is true, but not if we just quit listening to the 'urges' by The Holy Spirit warning us. We are given The Holy Spirit to help us understand God's written Word, and thus like Jesus said, if we stay in His Word, then we become His disciples, and the Truth will make us free.
John 8:31-32
31 Then said Jesus to those Jews which believed on Him, "If ye continue in My word, then are ye My disciples indeed;
32 And ye shall know the truth, and the truth shall make you free."
KJV
That very last phrase, "and the truth shall make you free," is often quoted, even by the non-believer sometimes. But it's that part in red which Lord Jesus said that is HOW that truth will make one free. And word "disciples" is from a root word that means 'discipline'.
