Because it's easy to preach and hard to put into practice.
Some people want the best for others than themselves and so that's why people tend to give advice to others and not follow up on it them selves.
It requires more effort than "do what I say not what I do"
Because doing is harder than saying.
Do as I say, not as I do ...
people who are learning anything need to repeat certain things till you get it,,but I have played guitar most of my life, do I know it all?
no ,and when I try something new I have skills, but old techniques make your brain used to one way and now I add something new I have work to get the new sometimes go against a way i have been using for years ,,a sudden change in timing a note that would normally sound sour to me is now bending or building up to the final note and it is great,,,new christians step out in faith and as they learn to trust God ,its not them that saves souls, they begin to come in harmony with what they speak ,,if they are Gods ,
,but satan has an agenda too and that is to make everything God said to look like a lie,,wolves in sheeps clothing ,,,they say they are a sheep till you trust them and then thy hurt you ,and God allows this so you learn to make sure next time if it really is a sheep,
many real sheep have been hurt and their testimony darkened by pretenders whose agenda from the start was to make you say "Now you see why I don't trust Christians ,,,,You see and you wanted to help those kids but how do we know where the money is going,,,that Church is open on the wrong day,,No one really hears God ,,only people who are weak minded ,,who needs to be on some kind of medication would believe all that ,,but that is why even those who think they are worthy to judge the fruit of the children of God are really hoping they will fail,, so you don't feel so bad at how your are ,if you judge fruit you should at least know what good fruit looks like and the desc
Most people don't really know enough of Gods word to know a wolf if he isn't in sheeps clothing,,stand there smelling like a wet dog ,drooling ,ready to pounce and you are calling friends to come hear the prophet ,,never trying the spirit to see if he is from God and does everything come to pass just like he said ,,,because if any of the prophecy is wrong it is false and we are told once this is discovered, you are told not to even eat with him and warn other children of God he is a false prophet,,many bad people in this world ,,but a bad real Christian or person of faith,,,is still saved and working at doing better ,,but the unsaved who sit in judgement are twice damned ,,first for knowing and not changing ,,and for harming even the least of one of His
They are hypocrites