Matthew 5:23, 23 The Lord Jesus is speaking of bringing a physical offering to the altar. This is an OT outlook as they were still in the midst of the old covenant. He is exhorting that if your brother has something against you – not if you have sinned against your brother – you must not come to the altar.
Sin bars the way to God. We do not now bring a physical offering to a physical altar, but prayer is still a sacrifice in a holy place in the presence of God. Hebrews 13:15 calls praise a sacrifice from the lips of believers. Christ’s admonition, His spiritual command, is still very appropriate. We have a blessed privilege of coming before God through the death and resurrection of Christ. We have the way paved to the altar by His blood, and we have a sacrifice of prayer to lay there. Sin cannot live there. We can’t just tromp in and blast out our needs and desires. It is true that Christ’s righteousness covers sin but we must be sensitive to sin in coming into God’s presence.
As Moses had to remove his shoes in God’s presence in the burning bush, the believer must remove his sin in God’s presence for prayer. This is another reason for secret prayer. As we approach the mercy seat over a period of time and come into God’s presence over a period of time, we become more aware of what needs to be dealt with in our lives. Self-examination and repentance is the “shoe removal” of secret prayer. The way in which we have consciousness of sin is because we have been given the law of God in the inner man, the knowledge of the reality of who God is that we cannot ignore. Psalm 66:”If I regard iniquity in my heart…” The Psalmist is not saying “sin on my hands”, “the intention of sin” – he is saying that he cannot condone sin in the inner man. If the believer is not maintaining the knowledge of who God is in the inner man, God will not hear prayer.
There must be a reconforming of the soul to God’s image. Only the believer can conform to the image of God in the inner man. Only the believer can know the distinction between what is sinful and what is not. And when there is the presence of sin, the believer will be made to know that. We will not attempt to come into God’s presence with the knowledge of sin.