By Grace the elect are saved and their sins are covered...not those who willfully (ie: deliberately) continue in sin. Read Hebrews 10:25-31,1 John 3, and 1 John 5
A Child of God will likely not sin, but it does happen. A Christian can be backslidden. We all sin. One sin is not worse than another in God's eyes, except for the sin of unbelief.
You sin. We all do. Considering that God does not see one sin as worse than another, for we have all fallen short of the glory of God, our "righteousness" is but filthy rags, if not for the blood of Christ. Thus, one sinning willfully and defiantly to God, but of whom had a true conversion, is no less covered under grace than the person who tries to never sin. Of course, we should try to not sin and to be more Christ-like, but you are taking the verses out of context, in my opinion, looking at them by themselves and not in context of the entire Bible.
The elect are those who have answered the call. They are the children of God, the saved. Yes, the elect's sin is covered, as they are children of God.
Here's real Scripture brother...unless this too is "unbiblical"
Hebrews 10:26
26 If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left
This is not talking about people who have accepted Christ, but about people who have rejected Christ after hearing the knowledge of truth.
1 John 3:9
9 No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God.
You never sin? We all do. If not for God's grace, we'd be without hope. However, we have hope because God justified us to Himself though the blood of His Son, Jesus Christ.
In Jesus, we are a new creation. We are saints, not longer defined as a sinner, for God's blood has eradicated that sinful nature. We are no longer condemned.
Since God's seed is in us, and since God cannot share a place not of the spirit, our sins are as though they do not exist. Thus, we are blameless before God and without sin (hence, no sin; cannot sin in terms of it resulting in condemnation) because we have been born of God. Consider the following verse:
1John 3:5 And ye know that he was manifested to take away our sins; and in him is no sin.
There is NO SIN in Christ. Thus, it's as if we don't sin. It's been covered. Now, this isn't free reign to live a sinful life, but it does mean that grace has us covered. Coupled with verses that indicate that salvation is eternal, it obviously matches.