Saying it in another way ...
1): Christians are already as righteous as they can possibly be from God's perspective, because God's righteousness was imputed to them through Christ's death, burial and resurrection. But that's just HALF of the matter. God NOW expects them to start diligently walking out their righteousness! (Obedience to His New Testament commands, in other words). If you consider yourself to be a Christian, but the sin/s you keep committing is no big issue to you ... is it possible you aren't truly a Christian after all and just haven't figured it out yet? But if you ARE a Christian and are convinced you are, then it's possible that you are just looking to Jesus to be your "fire insurance policy -- keeping you from going to hell on the Judgment Day) rather than also purposing Him to be Lord of everything in your life. Proverbs 28:13 states it as simply and clearly as it can be summarized when it comes to sin in our life. (Sin is not only to be confessed to God, but ultimately forsaken. Satan does not want Christians realizing that!)
If one is hardly interested in bringing and giving God glory with their time, talents, treasures, thoughts and attitudes, actions ... overall obedient behavior in other words (See: Psalms 96:3), it may be a HUGE reason why God has shut off His blessings in your life.
Scripture tells us that Jesus came to destroy the works of the evil one - Satan (1 John 3:8). Meaning? He came to destroy the works of the devil - the evil - in you and I. Satan's evil will greatly prosper and expand around this planet until he is locked away in hell, the Bible assures us. But evil is not to be ignored in true Christians. We are to be working diligently with our Lord and Savior to put to death the sin/s that so easily have their way in our lives. Daily we're to make this top priority in our relationship with Jesus Christ to the glory of God our heavenly Father.
2): Somehow availing themselves to the Holy Spirit in helping win lost souls to God the Father through a personal relationship with Jesus Christ. All Christians are called in some capacity to be witnesses of the truth of the message of the cross. Anyone can place Christian tracts where others can find them. It's a GREAT start! Doing the work of evangelism is not just allocated to Evangelists and Pastors. If the peace of God is not on your life, nor His favor, it may we be that God is trying to send you a message. Pray about helping win souls to Jesus Christ FIRST priority in your life - not a priority way down your list of importance's. You'll be amazed how quickly God's blessings can get placed on your life once you change life's priorities.
3): And/or helping untaught - new (infant) - Christians to grow in knowledge, understanding, and wisdom of God's Word properly applied to all of life's situations ... then they are pursuing a false and worthless Kingdom of God and are truly following the "Kingdom of Self," which is the "kingdom of darkness" - eternal darkness at that. The Bible also refers to that "kingdom" as Satan's kingdom, I hope you realize.
A few Christians do most ALL the work of teaching (discipling) infant Christian converts. EVERY true Christian should be eagerly trusting God to use them however He desires in the discipling process. If a person doesn't place that a top priortiy, God may not be so interested in granting you the desires of your heart, nor blessing your efforts to move ahead in life.
As we make it our FIRST priority to do what pleases God (Helping to advance His Kingdom rule in the lives of other people, in other words, by helping reach lost souls to Christ, and then helping them grow in understanding and application of God's Word), He becomes a lot more motivated to do what please us. We can quote the scripture verse all we want: "God wants to give me the desires of my heart" - but a major CONDITION comes with it. Are we making it our TOP priority to engage in the work of HIS Kingdom first in our life, or aren't we? If we aren't, our hearts' desire may not get realized, sad to have to say.
If you want a clearer revelation concerning Psalm 37:4 - "Delighting yourself in the Lord" is BEST wisely understood by saying it this way: "Delight yourself in the PRIORITIES of the Lord, (What is most important to God, in other words) and then He'll be a lot more interested in granting you many of the desires of your heart, providing they will help motivate you to be more diligent Kingdom investors."
Most of us Christians need a heart change. We need to realize it is selfishness that holds most of us back from being engaged in the advancement of God's Kingdom in the lives of others. Once we will admit to ourselves and God that we are selfish core to our being, confess that frequently to God, then ask Him to place in our being HIS Kingdom advancement desires ... we may remain joyless, frustrated Christians our entire lives, if we remain Christians at all.