What is the Biblical argument used by Evangelical Christians against the Catholic doctrine of the invocation of the saints?
We can see a principle of equality with other Christians (and even angels) in our work for the Lord that would preclude elevated status for some.
Revelation 19:10 And I fell at his feet to worship him. And he said
unto me, See thou do it not: I am thy fellowservant, and of thy
brethren that have the testimony of Jesus: worship God: for the
testimony of Jesus is the spirit of prophecy.
Each Christian has direct access to the Father and needs no intermediary.
John 14:23 Jesus answered and said unto him, If a man love me, he
will keep my words: and my Father will love him, and we will come unto
him, and make our abode with him.
John 16:26-27 At that day ye shall ask in my name: and I say not unto
you, that I will pray the Father for you: For the Father himself
loveth you, because ye have loved me, and have believed that I came
out from God.
We have the Spirit of God living within us. We have no need of some dead person to talk to God for us?
John 15:26 But when the Comforter is come, whom I will send unto you
from the Father, even the Spirit of truth, which proceedeth from the
Father, he shall testify of me:
While the Bible does use the word “saint”, it is used of all believers and not of just special believers. It is meant to distinguish those who have been set aside from the world and not set aside from other believers. All “saints” are expected to grow into Christ-likeness.
Ephesians 4:11-12 And he gave some, apostles; and some, prophets; and
some, evangelists; and some, pastors and teachers; For the
perfecting of the saints, for the work of the ministry, for the
edifying of the body of Christ:
The most convincing verse is;
1 Timothy 2:5 For there is one God, and one mediator between God and
men, the man Christ Jesus;
Prayer can be hindered by sin, bad conduct, and wrong motives.
Psalm 66:18 If I regard iniquity in my heart, the Lord will not hear
1 Peter 3:7 Likewise, ye husbands, dwell with them according to
knowledge, giving honour unto the wife, as unto the weaker vessel, and
as being heirs together of the grace of life; that your prayers be not
James 4:3 Ye ask, and receive not, because ye ask amiss, that ye may
consume it upon your lusts.
However, there is no record of prayers made to saints. All prayer is assumed to be to God.
1 Peter 3:12 For the eyes of the Lord are over the righteous, and his
ears are open unto their prayers: but the face of the Lord is against
them that do evil.
We can solicit prayers from other believers and we know that prayers from those who are closer to God are effective.
James 5:16 Confess your faults one to another, and pray one for
another, that ye may be healed. The effectual fervent prayer of a
righteous man availeth much.
However, there is no record of anything done by those who are dead other than wait for the resurrection.
Our communication with God is described as one of a child with his father not of a child through a servant to his father.
Galatians 4:6 And because ye are sons, God hath sent forth the Spirit
of his Son into your hearts, crying, Abba, Father.