What does the Bible verse that says we are to lay aside every weight and sin mean? What is this weight the author is talking about?
The Cloud of Witnesses
The author of Hebrews wrote, “Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us, looking to Jesus, the founder and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God” (Heb 12:1-2), so the question comes up, “What is “every weight?” that we are to lay aside in our race? First of all, the author starts off with the word, “Therefore,” so what’s the “Therefore,” there for? Therefore means we look backward at what was just said or written, and in this case, it’s Hebrews 11. That’s where the author displayed the heroic faith of saints gone by, and how they endured even under extreme persecution. Many died for their faith, so the author wants us to look back at them as our cloud of witnesses, or examples of running the race with endurance. They were able to do that because they kept “looking to” God as we look to Jesus Who Himself endured the shame and the pain of the cross for the “joy that was set before Him.” It’s set before us too, so focus on Jesus at the finish line. This verse does not say those witnesses are watching us, any more than our lost loved ones are watching us from heaven. I’d hate to think my mother could see me in all my shortcomings and sins. I think the author is trying to impress the Messianic Jews or Hebrews that they can endure if they lay aside the sin and weights that slow them down, and fix their eyes on Jesus. That’s good advice for us too!
We know we’re to lay aside every sin, but we also know we’ll never be sinless this side of the kingdom. We should sin less, but never becoming sinless. Thankfully, God looks at us as if Jesus’ own righteousness is ours (2 Cor 5:21), but we are still told to lay aside every sin because it slows us down, so how does the Bible define sin? The Apostle John writes, “Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness” (1 John 3:4), so sin is breaking God’s law, more specifically, the Ten Commandments. The Apostle Paul asks, “What then shall we say? That the law is sin? By no means! Yet if it had not been for the law, I would not have known sin” (Rom 7:7), so the law shows us what sin is. This means we have no excuse when we steal or lie, so clearly we are told “to lay aside every weight, and sin which clings so closely” to us, and that means we avoid breaking God’s law. If not for the law, we’d never even know what sin is, so that we could avoid it, so sin is breaking God’s law, and the law tells us what sin is, so now we know what to lay aside. We will fall, yes, but unlike before we were saved, we’ll fall into sin, but we won’t dive into it and swim around and enjoy the water
Sin or Not?
Many years ago I remember hearing about an old man who came forward during church services on Sunday night. As he came forward, the deacon stopped him and reached into his shirt pocket and crushed his pack of cigarettes, and whispered, “Not in here!” Thankfully, the man still came forward and put his trust in Christ. Later, the pastor saw the man after services and handed him some money to replace the cigarettes. He also apologized for the deacon’s behavior. After the man joined the church, the deacon apologized too. To the deacon, this must have seemed like the unpardonable sin, but is it? Who says so? Yes, our body is the temple of the Holy Spirit, however that verse (1 Cor 6:19) was in the context of the Apostle Paul’s rebuke of the Corinthian church for their sexual immorality. That verse could apply to drunkenness, smoking, drugs, and other things, but to use it against someone to say that smoking is sin, or drinking a beer or any alcohol (even one glass at dinner) is sinful is something that the Holy Spirit is better off convicting them of. If it is sin to them, leave it to the Spirit and their conscience, but if it isn’t sin to them, why should we make it so? I don’t drink, but I don’t condemn my brother for drinking a beer at a bar-b-q. We are all being sanctified and taking differing amounts of time, and we won’t all overcome at once. No one will. 
I believe weights might not be sinful in and of themselves. It might be okay to have a drink at dinner, but when that drink becomes two or three, or alcoholism runs in the family, it’s a weight that’s just not worth the risk. I don’t drink, but I don’t judge others who do. I don’t drink because others might say, “Well, the pastor drinks, so it must be okay.” My own conscience has doubts about drinking, so I don’t, but my own conscience can’t determine what’s right and wrong for you, aside from the obvious sinful practices mentioned in the Bible (Gal 5:19-21). Only then can I share my concerns about your sin, and if that doesn’t work, I’m going to see if someone else would see would go with me (Matt 18:15-20), but that’s done in love. Some weights might be our job, shopping, sports, and even worse, when you have children you can run yourself ragged getting them all to the games on time (soccer, baseball, volleyball, etc.). Other weights can be working too long and too hard to the detriment of the family. God is pleased when we work hard, but it becomes a weight when it takes away from our family. It’s not sinful to work, but a negligent parent can be a heavy weight for a family, and negligent parenting is sin.
Many do not know the difference between weights and sin. They are not the same, it would seem, because Paul mentioned them separately, so it seems, a weight is different than sin. Paul knew the church at Rome had problems with those things too as they were judging their fellow brothers and sisters, so he wrote, “Who are you to pass judgment on the servant of another? It is before his own master that he stands or falls. And he will be upheld, for the Lord is able to make him stand. One person esteems one day as better than another, while another esteems all days alike. Each one should be fully convinced in his own mind” (Rom 14:4-5). I can’t have doubts about things you are doing where the Bible is silent, and you can’t have doubts about things I do where the Bible is silent. Perhaps this is why Paul said that “whoever has doubts is condemned if he eats, because the eating is not from faith. For whatever does not proceed from faith is sin” (Rom 14:23).
Here is some related reading for you: What Does Being Free From Sin Mean? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible : English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.