God has replaced the Law (Old Testament) with his Spirit (New Testament).

OLD WAY OF LIVING WAS BY EFFORT TO OBEY THE LAW

In the Old Testament, God gave laws to his people for governing their relationships with him and with each other. These laws – generally referred to as ‘the law’ – included the Ten Commandments and hundreds of supplementary ethical and ceremonial rules covering nearly every aspect of daily life.

But it was impossible for anyone to fully comply with the law. No one could be that good; not even Moses. The purpose of the law was to define sin and to demonstrate that everyone – even the best of us – is a sinner. When a person sinned, he had to offer a sacrifice to God in order to obtain forgiveness (see Topic 33) and then he would start all over again trying to be good.

Fortunately, obeying the law is no longer the key factor in our relationship with God. Now faith in Jesus Christ is the key factor.

JESUS CHRIST HAS TOTALLY FULFILLED THE LAW FOR US

Referring to the Old Testament laws, Jesus said, ‘I have not come to abolish them, but to fulfill them.’

The New Testament explains that Jesus Christ is available as our substitute (if we personally claim him as substitute), in which case God looks at Jesus’ life (perfect!) and imputes his righteousness to us. Thus, Jesus Christ has fulfilled the law for us because God is willing to judge us on the merits of the substitute righteousness rather than on the demerits of our own sin.

The big difference between the Old Testament (old way) and the New Testament (new way) is that formerly people had to work at being good by following the law, but now we’re declared good because Jesus Christ (if we ask him) is our perfect substitute. His life is exchanged for our life (see Topic 54).

If we personally (by individual decision) accept Jesus Christ as our savior, God accepts the perfect life of Jesus as though it were our own life, so that when we stand in judgement before God we’re without sin. It’s as if we had never broken a single one of God’s laws in our life!

As with most things in God’s world, this is profoundly simple but also profoundly complex. That’s why we need the Old Testament explanations of sin and substitution to adequately understand and appreciate what Jesus Christ did by fulfilling the law for us.

NEW WAY OF LIVING IS BY POWER FROM THE HOLY SPIRIT

Jesus told his disciples that he would send the Holy Spirit to help us with our daily living. (The Holy Spirit is part of God, without a body, who relates to us individually – see Topics 7, 8, 39, 41 and 44.) At the time Jesus said this, his disciples couldn’t even comprehend the concept of it, but now we understand and experience the reality of it.

The Old Testament law is still valid because it tells us the kind of thoughts, words and actions which are pleasing to God. We shouldn’t ignore the law today on the grounds that Jesus has fulfilled it or that it only applied to the Israelites. We still look to the great moral principles that lie behind the law.

But now these principles are worked out in daily living by the Holy Spirit, who literally resides within each Christian. It’s no longer a matter of self-effort but rather a matter of letting the Holy Spirit take control and good living comes quite naturally.

It’s no wonder that the core message of the New Testament is called the ‘gospel,’ a Greek word meaning ‘good news’ (see Topic 52). The good news is that we don’t have to struggle trying to obey the law in order to be acceptable to God.

Instead, we can take Jesus Christ as our personal substitute (savior) and receive the Holy Spirit to change our desires and empower us for good and dynamic living.