If we have a steadfast heart we will hold fast to something; we will not drift away. If our heart is steadfast for God we will hold fast to Him.  With this obvious thought in mind, what else will result from a steadfast heart for God?

 My heart is steadfast, O God; 
   I will sing and make music with all my soul. 
Awake, harp and lyre! 
   I will awaken the dawn. 
I will praise you, O LORD, among the nations; 
   I will sing of you among the peoples. 
For great is your love, higher than the heavens; 
   your faithfulness reaches to the skies. 
Be exalted, O God, above the heavens, 
   and let your glory be over all the earth.

Psalm 108:1-5

From David’s point of view, the obvious result of steadfastness for God is joy, singing, praise, testimony and lifting up the name of God before all Peoples. It would not appear that steadfastness for God results in long sad faces, a heavy sense of obligation, or mourning for all of the things we’ve left behind.

Will we sing with joy, praise Him with gladness and share our joy before all the people? Steadfast hearts include the response of the heart to His faithfulness and love, and that reaction is one of unfettered joy!