Why is praising to God a sacrifice?
Sacrifice means to kill. Sometimes we need to kill our pride etc. for praise in order to concentrate on Him. We need to devote ourselves to praise. That means to concentrate on a particular pursuit, purpose or cause. He, who is devoted to Jesus, will recognize his fleshy tendency. We need to practice persistent and patient praise. We need to discipline ourselves to praise God for every benefit He provides.

Hebrew 13:15 (Amp.)
Through Him, therefore, let us constantly and at all times offer up to God a sacrifice of praise, of which is the fruit lips that thankfully acknowledge and confess and glorify His name.

Let us look at this scripture more in detail: -

1. Through Him therefore

   1. Because Jesus is our High Priest - Hebrews 8:1

   2. Because Jesus is our sacrifice - Genesis 22:8; Ephesians 5:2

2. Let us constantly and at all times

   1. In Israel there was a continual offering through the morning and evening. The Levites were to sing praise during their time of sacrifice - Psalm 141:2

   2. Takes a sustained burning to consume the whole burnt offering - Exodus 29:15-18; 2 Chronicles 29:28

3. Offer up to God a sacrifice of praise
   

   1. With our hands - Psalm 33:2-3; Psalm 119:48; Psalm 47:1

   2. With our mouth - Psalm 34:1; Psalm 132:1

   3. With musical instruments - Psalm 150

   4. With our posture - Psalm 135:2; Psalm 95:6; 2 Samuel 6:13-14

   5. With our body actively involved - Psalm 63:2-6

   Romans 12:1 states that submitting our bodies, as a living sacrifice is reasonable worship. We need to employ singing both with the spirit and with the understanding, using speaking, bowing, kneeling, raising our hands, dancing, applause, musical instruments to enhance expression of worship.

4. Of which is the fruit lips
   Not just referring to audible praise but also to the fulfilling of daily praise to the Lord - Psalm 50:14; John 2:9

5. That thankfully acknowledge
   Thankfulness is the attitude while praise is the action - Leviticus 22:29; 2 Chronicles 29:31 To praise the Lord means to speak well of God. With exuberance and enthusiasm to others and to Him for what He has done in your life. Praise the Lord is a command to extol God's virtues and exalt Him because of His mighty acts. A praise gathering is a celebration. Worship the Lord with all your heart and mind. Worship addresses God directly expressing reverence for His nature, character attributes and power and grateful praise for all He is and does.

6. And confess
   To be in right standing with God we are to confess our sins and it will be forgiven - Matt 10:32; Psalm 32:5
   

7. And glorify His name

   1. His name represents what He can do - 1 Chronicles 16:8

   2. His name represents what is like - 1 Chronicles 16:10

   3. Those who received mercy - Romans 5:9

   4. It requires a commitment from us - Psalm 86:9,12

   5. Glorify His name in difficult times - Isaiah 24:15

   The Scriptures is there to shape us, to shape our thinking and we need to denote time for prayer, waiting upon the Lord, worshipping Him by our praise and thanksgiving.