Do you think Christians sin?
If so, what common unconfessed sins do you think Jesus forgives?
For example: Do you think lying, or cursing, or inappropriate content (lusting), hating, coveting are automatically covered by the blood of Jesus by having a belief alone on Him?
The way of the cross is like a sea saw. It is weighted over time. There are two sides to us. The flesh, and the Spirit. If we invest purely in the flesh, we begin to be over come by it. If we weight to the Spirit, by prayer and obedient living, we draw ourselves upward away from death. Jesus said "Pray that you enter not into temptation, for the flesh is weak but the Spirit willing". That verse is loaded, as we pray, make God our focus, we will not sin as much. If we ignore God, the weak flesh will dominate us.
Then we need to look at how God judges in the end. He says of the last days,
2Th 2:9-12 The coming of the lawless one is by the activity of Satan with all power and false signs and wonders, and with all wicked deception for those who are perishing, because they refused to love the truth and so be saved. Therefore God sends them a strong delusion, so that they may believe what is false, in order that all may be condemned who did not believe the truth but had pleasure in unrighteousness.
Note that God Himself sends people Strong Delusion, that they will not believe the truth, and why, the scripture is clear, they had pleasure in unrighteousness, and sin.
Why is this important? Well yes a Christian is saved by Grace, not by what they do or do not do. But in reality we are not saved 100% by Grace, we are saved by our connection to Christ, our love for the truth. If we love sin more than God, Jesus may spit us out of his mouth.
Rev 3:15-16 “‘I know your works: you are neither cold nor hot. Would that you were either cold or hot! So, because you are lukewarm, and neither hot nor cold, I will spit you out of my mouth.