Proverbs 14:12 "There is a way which seems right to a man, But its end is the way of death."
I remember one time when I was young I was visiting a church with a friend and his family, and I had been feeling that I wanted to give some money to the Lord since I hadn't been to a church in a long time and there hadn't been a chance for me to.  So this one day when I visited this church I brought some money along thinking, maybe there's a chance to give to God.  At the end of the service they passed around an offering box, and I felt good putting that money in the box, like I had given to God.  But then I was shocked when after the collection, the visiting preacher there announced he wanted to pass the offering boxes around one more time, so that the pastor (who was out of town at the time) would come back and be happily surprised!  I may have been young but even I could recognize the evil of wanting to "make pastor happy by giving big double-offerings."  But there was no taking the cash back out of the box now.  What's done was done, I had already wasted the money by giving it to that church.  Soon after I found out unsurprisingly that the church and the pastor were preaching the prosperity gospel, and the pastor was living very lavishly from his church earnings.  I felt so horrible that I dishonored the Lord with HIS money because I didn't listen to Him and I just jumped at the first thought of what I assumed was good.  So I had to repent of that.
I regret giving that money to such a church, but I'm thankful that it taught me to be careful with God's money from there on out when giving it somewhere.  And it taught me not to just assume I know what's good and right, without seeking the Lord first.
One characteristic I've seen in the godly saints I've known and the ones who I read about (both in the Bible and in church history) is that: when making decisions, they don't immediately assume they know the right way.  They don't make quick, off the cuff decisions.  They don't get excited too quickly about some new path that opens up to them that seems good.  They recognize their immense lack and ability to completely fall short apart from God, and so they are careful to go to the Lord for awhile and listen, as they go forward in life and make decisions.  In other words they are 'led by the Spirit' (Rom 8:14).  They are "needy" for guidance.  "Blessed are the poor in spirit (needy)" (Matt 5:3).  They are aware of their shortcoming and absolute incapability to do anything good apart from God (even Jesus was like this! John 5:30).
Proverbs 16:25 "There is a way which seems right to a man, But its end is the way of death."
This is exactly the same verse (word for word) as the previous verse we saw in Proverbs chapter 14, written two chapters apart in Proverbs.  The fact that this verse is written twice in exactly the same way emphasizes to me how important it is.
So I was reminded to beware of the "this seems like it's right" attitude.
One thing that's helped me avoid that careless attitude, is if I very quickly feel I have peace about some important decision, first give the Lord a period of time with the decision (before acting on it) to totally submit it to Him, and allow Him to override it.  Allow Him a chance to reveal to me if that's what He's really speaking, or close a door.  Keep it surrendered on the altar.  Then at the end He can either confirm it or show me otherwise, but either way I can move forward with peace that it was His decision, and not just "the way that seemed right" to me.
If I had that attitude when I was visiting that church when I was younger I believe I could have easily recognized "This is God's money, and I'm about to do something with it... I need to ask Him, and be careful with it."  I believe He would have stopped me and told me not to be hasty.  He could have showed me something about the very "showy" music being played there and put a hesitation in my heart, or He could have warned me that I didn't know enough about the church yet to be able to make a wise decision.  He could have spoken something to me about foolish youthful zeal, which does a lot on the outside, but accomplishes nothing for the kingdom of God.
Most work and good works for the Lord today are like a man rowing in a canoe in the pitch black dark of night, and on the last day when the morning sun comes up he will see that his boat was tied to a tree the whole time and all his labors were wasted, and he got nowhere.  If he would have only listened to the One who can see in the dark!
The Lord will guide us in the right way, and will produce real lasting fruit for Him, only if we lean on Him and listen "constantly at His gate" (Prov 8:34) so that we can know we're in His will before going forward.  Even if we don't hear a 100% clear word from the Lord right away, we can at least listen for a little whisper and even if we are wrongly hearing or make a wrong decision sometime, as long as we are sincerely wanting to do His will and not ours, we honor Him with the fact that we went to Him first before taking a step.  Because a good Father is pleased by his child not necessarily getting perfect grades, but trying their best.  And we have the Best Father!
Colossians 1:9 For this reason also, since the day we heard of it, we have not ceased to pray for you and to ask that you may be filled with the knowledge of His will in all spiritual wisdom and understanding, 10 so that you will walk in a manner worthy of the Lord, to please Him in all respects, bearing fruit in every good work and increasing in the knowledge of God;