It is by Him that believers can please God, and know how to please God, only by His righteousness, found in His Holy scriptures and by God's wisdom. This truth is of vital importance.
According to this verse, and all throughout the New Testament; serving, pleasing, obeying, loving, exhorting, etc. can only be done through the strength and energy of God. This idea is clearly seen in Philippians chapter 2:13. The Greek word translated " worketh" is ἐνεργέω (en-erg-eh'-o). It is God that gives us the energy (literally: to put forth power) both to will and to do of His good pleasure. This verse assures believers that God provides the will and desire, but also the ability to perform that which is pleasing in His sight. The human voice is the oldest and first instrument created by God for His pleasure. It didn't take long for men to figure out the various ways that the voice can be utilized and many artists still utilize their voice in many different ways, and to change the message of a song.
The next piont we see in Hebrews 13:15 is that worship, particularly with the voice, is to be a sacrificial offering. Not all offerings are sacrificial. They can be selfishly performed, and for the gain of one's own benefit, whether monetary or otherwise. When offering to the Lord, He wants if to be a sacrifice. Usually, when the offering is from the heart, it is automatically sacrificial. Singing to God is never usually thought of as a sacrifice, simply because it is so common today, and to sing...anything. Many, many christians may be and probably are singing their hearts to the Lord, but the message of a song or hymn can very easily be changed simply by the voice. It is a sacrifice to sing to the Lord, and in following the principles of His word.
Who do we sing praise to? Well, the only One that deserves praise and adoration. God is worthy of our praise and desires His children to give voluntary praise. It's amazing to me to think of this, even though there is nothing good that men can do.
Another important fact, and this was mentioned in my previous post, is that the worship of the believer needs to be continual. The Literal translation of John 4:24 brings this out nicely, but the writer of Hebrews reiterates this. To worship God continually can not be stressed enough. So often the stresses and busy-ness of life occupy our time and takes us away from worshipping the Lord. It is absolutely necessary to abide in our relationship with Christ so that Satan doesn't get a foothold in our life, especially when trials greet us.
What is it that believers need to offer, sacrificially, to God? The fruit of our lips, according to Hebrews. To further my understanding, I wanted to remind myself what "fruit" was exactly. This Greek word has the idea of being advantageous or something that is profitable. This is the first real mention of the use of the voice in this verse and, of course, refers to what we say, but also can be applied to how it is said. Take for instance the word "fine". When a person is asked how they are doing and respond with "fine", it can be said numerous ways. Imagine asking a person how they are and they answer "fine" in an unabrasive, polite, and jolly tone. It's logical to conclude that the person is truely fine and nothing is bothering them. In fact maybe they are happy and excited about something. On the other hand, if a person answers in a harsh, abrupt and angered tone, that person is clearly not fine. These examples show the difference between what is pleasant speech as opposed to unpleasant. Of course, this is a very small scope in making this piont, but it does make the piont and singing to God needs to be offered sacrificially, continually, and with the fruit of our lips. (The what and how)
There is one more item listed in this verse and that is thanksgiving. Many, when reading this verse, associate giving thanks to be the fruit of our lips. Certainly giving thanks is a fruit. Speech, as a whole, can be fruit or can be merely candy. We all know that candy is sweet but does not nourish or fulfill. Therefore candy is not very profitable. In addition to our speech should be added another fruit, the fruit of thanksgiving. Specifically, in this verse thanks be to the name of God. The names of God throughout scripture reveal His character and just to reflect on these names are a blessing. Whatever is going on in our lives, thinking about the names of God and their meaning is a huge comfort and assurance of who we have an eternal relationship with.
Psalm 7:17 "I will praise the LORD according to his righteousness: and will sing praise to the name of the LORD most high."