What are 'presumptuous' sins?
Num 14:42-44 Do not go up, because the LORD is not with you. You will be defeated by your enemies, (43) for the Amalekites and Canaanites will face you there. Because you have turned away from the LORD, he will not be with you and you will fall by the sword." (44) Nevertheless, in their presumption they went up toward the high hill country, though neither Moses nor the ark of the LORD's covenant moved from the camp.
Moses is saying 'God is not going to be with you, so why are you pursuing this, why are you trying to go into the Land?' He also said 'The Amalekites are there waiting for you'. Do you remember when we looked at the Amalekite story; there will always be an Amalekite there to hinder your walk with God. How was victory won over the Amalekites? Surrender! Whose battle was it when they fought the Amalekites? God's! Moses isn't going to leave the camp, but they presume to go anyway. That word 'presume' caught my attention. The dictionary meaning of 'presumptuous' is to do something that one has no right or authority to do. To presume is bold, insolent behavior. What it really means is 'I will do what I want regardless of the consequences'. And this is what the nation is doing. Moses is saying 'Look, don't do it' but they said 'We are ready; we are going to go anyway.' So they presumed to go up to the mountain top. It is that independent self-life that we have; that proud attitude which says 'this is what I am going to do because I want to do it.' There are other examples of presumption in the Bible. Cain was presumptuous when he offered a sacrifice to God in his own way; taking crops which he had grown for the offering when he knew that God required an offering of a lamb. The Tower of Babel is another - and the first attempt at world government on earth. They presumed to build this tower up to the heavens where they could have a centre for everyone to be located, after God had specifically told them to spread abroad in the earth. Because of this God came down and said 'what is happening here is not right' so He confused the languages and sent them out into the whole earth. Nadab and Abihu, Aaron's sons, offered profane fire before the Lord. They presumed to take the position that they didn't actually have that of offering sacrifices to God. A couple of chapters over in Numbers we have Korah's rebellion, which is the same sort of instance of people putting themselves into a position which they have no right to be in. So these are all instances of presumption which is a type of sin that we need to be aware of.
Psa 19:7-13 The law of the LORD is perfect, reviving the soul. The statutes of the LORD are trustworthy, making wise the simple. (8) The precepts of the LORD are right, giving joy to the heart. The commands of the LORD are radiant, giving light to the eyes. (9) The fear of the LORD is pure, enduring forever. The ordinances of the LORD are sure and altogether righteous. (10) They are more precious than gold, than much pure gold; they are sweeter than honey, than honey from the comb. (11) By them is your servant warned; in keeping them there is great reward. (12) Who can discern his errors? Forgive my hidden faults. (13) Keep your servant also from wilful sins; may they not rule over me. Then will I be blameless, innocent of great transgression.
David makes a distinction here between secret sins and presumptuous sins. Secret things are really those things that we do which only we know about and which fall short of the glory of God. They are the things that we do just because we are fallen and have a sinful nature. But there is a distinction here between those sins and what David referred to when he said 'Keep back your servant also from presumptuous sins.' Presumptuous sins are those that we talked about, sins that are really born in that self attitude of pride and arrogance. I am going to do this because it is something I want to do.'
Has anyone ever felt that they shouldn't, before God, be doing something, but are going to do it anyway? Lots of Christians get into trouble in many different areas just by making really bad decisions. And when it all turns to custard and the consequences begin to hit home, they want God to rescue them. Sometimes He does and sometimes He doesn't. Sometimes God allows those consequences to fall. David here is saying 'cleanse me from those sins that I do wrong, but keep me back from presumptuous sins.' This is something that only God can do as you yield your life to Him. He can hold you back from those independent decisions that you make which leave God out of your life.