"But woe to you Pharisees! For you tithe mint and rue and all manner of herbs, and pass by justice and the love of God. These you ought to have done, without leaving the others undone" (Luke 11:42).
Imagine the time and patience it took to measure the herbs that one had grown, determine what a tenth would be, and take that portion to the priests as an offering to God. This was an admirable attention to detail. Jesus often condemned the Pharisees, and rightly so, but please note that Jesus was not condemning the Pharisees for tithing their herbs. Jesus was condemning them for neglecting justice and the love of God. They were hypocrites because they gave attention to details regarding the tithing of herbs while ignoring important things like justice, mercy, and faith (Matt. 23:23). The Lord's conclusion is that they should have been both tithing and practicing justice and love. They were not to leave any of it undone.
From time to time I hear people claim that we shouldn't "sweat the small stuff." The idea is that as long as we are doing the important things we don't have to worry about the details. As long as we have intentions to love God and our fellow man we are doing everything we need to do. To such people paying attention to details means you are following rules, and Christianity is not about "following rules." Rules mean law, and the Christian is not under law but under grace. I heard arguments like this when I was in denominationalism, and sadly these same arguments are being made by some of my brethren today.
Jesus did away with this line of reasoning when He insisted "These you ought to have done, without leaving the others undone." It does matter how we worship God. We do have to make sure all five acts of worship are included, and are performed in spirit and in truth. It is important that the local church be involved in the right kind of work, and that this work is carried out in the correct manner. It does matter how the church is organized, that a confession of faith be made before a baptism, that women not be allowed to take a leadership role during an assembly of the saints, that the Lord's Supper consist of unleavened bread and fruit of the vine, that members be present for every service they can attend, etc. It does matter that we go to a brother who has sinned against us, that we restore those who are overtaken in a trespass, that we withdraw from every brother who walks disorderly, that we test all things - holding fast to what is good and abstaining from every form of evil, that we "observe all things that I have commanded you" (Matt. 28:20).
The gospel does not release us from the need to give attention to details. The gospel calls us to a higher standard (see Matthew 5:21-48). We are to "give the more earnest heed to the things we have heard" (Heb. 2:1-4). Paying attention to the "weightier" matters of the law does not release us from any obligation to the rest of God's law. God's grace does not give us a license to be willfully ignorant or negligent. The details do matter with Christ (Matt. 5:18-19). Are we doing those things which we ought to be doing?