As I was clearing my inbox this morning I received an e-mail from a church member entitled “I find this helpful.” Not really sure what I might find, I opened the e-mail and to my delight found the Heidelberg Catechism! Hearing that church members are picking things up like this on their own initiative is enormously encouraging. For those of you like my friend who find the great reformation catechism helpful, you may want to go over to Steve Wood’s blog TreadingGrain. He posts a devotional from the catechism every morning.
11. Q. But is God not also merciful?
A. God is indeed merciful, but He is also just. His justice requires that sin committed against the most high majesty of God also be punished with the most severe, that is, with everlasting, punishment of body and soul.
 Ex. 20:6; 34:6, 7; Ps. 103:8, 9.  Ex. 20:5; 34:7; Deut. 7:9-11; Ps. 5:4-6; Heb. 10:30, 31.  Matt. 25:45,46.
12. Q. Since, according to God’s righteous judgment we deserve temporal and eternal punishment, how can we escape this punishment and be again received into favour?
A. God demands that His justice be satisfied. Therefore full payment must be made either by ourselves or by another.
 Ex. 20:5; 23:7; Rom. 2:1-11.  Is. 53:11; Rom. 8:3, 4.
13. Q. Can we ourselves make this payment?
A. Certainly not. On the contrary, we daily increase our debt.
 Ps. 130:3; Matt. 6:12; Rom. 2:4, 5.
14. Q. Can any mere creature pay for us?
A. No. In the first place, God will not punish another creature for the sin which man has committed. Furthermore, no mere creature can sustain the burden of God’s eternal wrath against sin and deliver others from it.
 Ezek. 18:4, 20; Heb. 2:14-18.  Ps. 130:3; Nah. 1:6.
15. Q. What kind of mediator and deliverer must we seek?
A. One who is a true and righteous man, and yet more powerful than all creatures; that is, one who is at the same time true God.
 I Cor. 15:21; Heb. 2:17.  Is. 53:9; II Cor. 5:21; Heb. 7:26.  Is. 7:14; 9:6; Jer. 23:6; John 1:1; Rom. 8:3, 4.
16. Q. Why must He be a true and righteous man?
A. He must be a true man because the justice of God requires that the same human nature which has sinned should pay for sin. He must be a righteous man because one who himself is a sinner cannot pay for others.
 Rom: 5:12, 15; I Cor. 15:21; Heb. 2:14-16.  Heb. 7:26, 27; I Pet. 3:18.
17. Q. Why must He at the same time be true God?
A. He must be true God so that by the power of His divine nature He might bear in His human nature the burden of God’s wrath, and might obtain for us and restore to us righteousness and life.
 Is. 9:5.  Deut. 4:24; Nah. 1:6; Ps. 130:3.  Is. 53:5, 11; John 3:16; II Cor. 5:21.
18. Q. But who is that Mediator who at the same time is true God and a true and righteous man?
A. Our Lord Jesus Christ, whom God made our wisdom, our righteousness and sanctification and redemption (I Corinthians 1:30).
 Matt. 1:21-23; Luke 2:11; I Tim. 2:5; 3:16.
read the whole thing here