And he [Jesus] said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment.” Matthew 22:36-38
The first calling of God on your life as a Christian is to love him with all your heart. If it is really true that you want to do something for God, your love for the Lord will remain the same, even if the door closes on what you hoped to do.
David wants to do something for God. But God wants something different for him. David really loves God, and so he says, “Lord, I wanted to build a temple for your glory, but if you want something different from me, I want to give what pleases you.”
Maybe the life to which God has called you is not the life you wanted to offer to him; but if you really love him, you will gladly give whatever he asks of you.
God’s ‘no’ to David building the temple was part of God’s ‘yes’ to the great contribution of David’s life, which was to establish peace by subduing the enemies of God’s people. Solomon could not have built the temple if David had not defeated the enemies and established peace. David could not have defeated the enemies and established peace if his time and energy had been taken up in building a temple.
What to you is a great disappointment may open the way to some other work that God is calling you to do. That work may not be what you would have chosen, but if you really love the Lord, you will find peace in following the path that he has mapped out for you.
Are you willing to do whatever God asks of you, even if it is not what you would have chosen for yourself?