Prayer is more like playing catch with God than groveling before a disinterested overlord. Prayer involves give and take, catching and throwing. Overlords mostly take; when they give they do so begrudgingly in the form of a loan; they expect payment in return with interest; overlord giving is only another means to taking.
God is not that way. There is nothing we can give him in return that he has not already given us. God is marked by eternal giving. To say “God is love” is to say he perpetually loves. To say this is to say he eternally self-empties. God is like a river: he is always flowing out but never running out. So, don’t worry, if you play catch with God he will always throw the ball back to you. It’s in his nature to play: the fruit of the Spirit is joy.
When I play with my son, it is my way of saying, “I love you.” In the same way, to play with God is to love God and be loved by him. I cannot see how one could love God with one’s whole heart and exclude playfulness with God from one’s life. Perhaps the greatest commandment could be rephrased: “You shall play with the Lord your God with all your heart, with all your soul, with all your mind and with all your strength.”
When praying, remember: God is not a bureaucrat. True prayer does not coincide with humiliation. Because God's holiness can only be seen in the light of his love, true prayer dignifies. Just as playing with another ascribes value to the other, so in prayer God reminds us how he delights in us, lavishes his love upon us and is pleased with his maturing child.
Pray with Lego now and then. It could remind you that you are God's joy and he can be yours.