First, because prayer is the natural outworking of love. Love lies at the heart of our being and our relationship with other people. In his Resurrection Jesus Christ overcame the power of death over creation, so our love is not limited and restricted by death. We can love beyond the grave. If we love, we pray. How could we not pray for those whom we love?
Second, we pray for the dead because we trust in God’s love. When we respond to God’s love in Christ and seek to serve him, we know that all sorts of things can get in the way and prevent us loving and serving him as we ought. Much about our earthly life is broken, fractured and incomplete. But we believe that 'neither death, nor life... nor anything else in all creation will be able to separate us from the love of God in Christ Jesus our Lord' (Romans 8.38-39) and so we have hope that after death, our growth to completion and fulfilment in God’s love does not stop. We can keep on growing, developing and responding to his love, until we see him as he is – until we come to what St Paul called ‘the full stature of Christ’ (Ephesians 4.13).
Third, we pray for the dead in order to realise that our Christian Family is one, unrestricted by time and space. We are one family in the Lord. Jesus said that his Father ‘is God not of the dead, but of the living; for to him all of them are alive’ (St Luke 20.38). If this is true, our prayers for the Church must be for the whole Church, whether alive in this world or alive in the 'life of the world to come'. When we pray for the dead, we demonstrate the truth that we are one.
Fourth, we pray for the dead because all people have sinned and 'fallen short of the glory of God' (Romans 3.23). We pray, then, that God, who is 'able to accomplish abundantly far more than all we can ask or imagine' (Ephesians 3.20) will forgive those who have died for those faults and failings which, in this life, have separated them from him and from their neighbours.
We pray for the dead in the faith of the Resurrection, believing that ‘eye has not seen, nor ear heard, nor the human heart conceived, what God has prepared for those who love him’ (I Corinthians 2.9). So in that trust and hope we continue to pray, ‘Rest eternal grant to them, O Lord, and let light perpetual shine upon them.'