Many people are not aware of the New Life of the Christian who has been called out of this life. "The way" is not entirely explicitly contained in Holy Sacred Scripture but also defined in the actions of the first Christians up to the present.
Rom 6:3-4 Or are you unaware that we who were baptized into Christ Jesus were baptized into his death? We were indeed buried with him through baptism into death, so that, just as Christ was raised from the dead by the glory of the Father, we too might live in newness of life.
Col 2:12 You were buried with him in baptism, in which you were also raised with him through faith in the power of God, who raised him from the dead.
Mk 12:26-27 "As for the dead being raised, have you not read in the Book of Moses, in the passage about the bush, how God told him, 'I am the God of Abraham, (the) God of Isaac, and (the) God of Jacob'? He is not God of the dead but of the living. You are greatly misled."
Heb 6:12 ... so that you may not become sluggish, but imitators of those who, through faith and patience, are inheriting the promises.
Heb 12:1 Therefore, since we are surrounded by so great a cloud of witnesses, let us rid ourselves of every burden and sin that clings to us and persevere in running the race that lies before us
1 Cor 13:12 At present we see indistinctly, as in a mirror, but then face to face. At present I know partially; then I shall know fully, as I am fully known.
1 John 3:2 Beloved, we are God's children now; what we shall be has not yet been revealed. We do know that when it is revealed we shall be like Him, for we shall see Him as He is.
1 Cor 11:1 Be imitators of me, as I am of Christ.
Phil 3:17 Join with others in being imitators of me, brothers, and observe those who thus conduct themselves according to the model you have in us.
Earliest Christianity has always defined prayer as conversation, as in conversation with God. Conversation, as any other act of communication ( e.g., talking, conversation, yelling, etc.), requires
a sign of the direction of the communication: one talks
to someone, communicates
with someone, prays
to someone, converses
with someone, yells
at someone, etc. Hence, praying to God, a Saint, the Virgin Mary indicates simply the direction of prayer communication. It is more a matter of grammar and understanding communication than acknowledging the worship of the receiver.
Prayer to a saint from the catacombs;
Early Fathers say very much on this as well, couple of short examples;
Tertullian (211) Wrote that Christians offered prayer and the Eucharist for the deceased on the anniversaries of their death.
St. Augustine (354 - 430) Neither are the souls of the pious dead separated from the Church, which even now is the Kingdom of Christ. Otherwise there would be no remembrance of them at the altar of God in the communication of the Body of Christ.
and a whole mine of other examples:
http://www.scripturecatholic.com/saints.html#tradition-I