The workers on night shift may have to come to church weary, but there is no reason why most of us can't plan to arrive rested and at our best... The Christian who goes to bed too late on Saturday night is going to rob himself and God on Sunday morning.
A weary body is usually the sign of a foggy mind. We must prepare our minds if we are going to listen to God's word with any degree of understanding and enjoyment... Preparation is essential to good listening. Yes, it demands discipline, including saying no to many Saturday-night invitations; but the results are well worth the sacrifice.
Warren Wiersbe's "God Isn't in a Hurry"