Mark 12:24 (NASB) Jesus said to them, “Is this not the reason you are mistaken, that you do not understand the Scriptures or the power of God?
In this particular passage the question has come up about marriage in heaven, and Jesus' response is a classic. This answer goes beyond the question that was even asked of Him. This answer is for every one of life's questions that we ponder on a daily basis.
II Timothy 2:15 instructs us to study the Word, so we can apply it appropriately. We often err in life because we don't know the Scriptures. The Bible contains answers for the saved person to live holy, correction when we've gone astray, and blessed hope when we are in despair. Even when asked for advice, we should revert to what God has said about a matter. Our opinions should be based on our understanding of the Word of God. Sure, we will still make human mistakes, but studying God's Word opens up our minds daily to fresh, new revelations and applications.
The second part of Jesus' answer explains the rest of our issues. We don't understand the power of God. The knowledge of the Word of God, coupled with the power of God will make us UNSTOPPABLE! The enemy can't defeat me if I understand the promises God has spoken over my life, and I know He is able to bring them to pass in His omnipotence (all powerful-ness). I can get back up after a failure, if I understand the lesson that God was teaching me and trust in His power to yet try again with what I've learned.
I don't have to keep making the same mistakes. I can study the Scriptures and understand the power of God, as they apply to my life. I can live a better life; I can be a better me, and that will bring glory to God. All I want to do is what's pleasing to God, and I can't know what that is without studying His Word and trusting in His power.