The concept of intercession also exists in (some forms of) Islam, albeit in a different way. It doesn't apply to prayer, but on the day of resurrection God has granted Muhammed the right to intercede on behalf of others. If intercession is possible through God's will, you could make the argument that God has also granted the right for saints to intercede on behalf of Christians.
It was narrated that Anas ibn Maalik said: Muhammad (peace and blessings of Allaah be upon him) told us: “When the Day of Resurrection comes, the people will surge with each other like waves. They will come to Adam and say, ‘Intercede for us with your Lord.’ He will say, ‘I am not fit for that. Go to Ibraaheem for he is the Close Friend of the Most Merciful.’ So they will go to Ibraaheem, but he will say, ‘I am not fit for that. Go to Moosa for he is the one to whom Allaah spoke directly.’ So they will go to Moosa but he will say, ‘I am not fit for that. Go to ‘Eesa for he is a soul created by Allaah and His Word.’ So they will go to ‘Eesa but he will say, ‘I am not fit for that. Go to Muhammad (peace and blessings of Allaah be upon him).’ So they will come to me and I will say, I am fit for that.’ Then I will ask my Lord for permission and He will give me permission, and He will inspire me with words of praise with which I will praise Him, words that I do not know now. So I will praise Him with those words of praise and I will fall down prostrate before Him. He will say, ‘O Muhammad, raise your head. Speak and intercession will be granted to you, ask and you will be given, intercede and your intercession will be accepted.’ I will say, ‘O Lord, my ummah, my ummah!’ He will say, ‘Go and bring forth everyone in whose heart there is faith the weight of a barley-grain.’ So I will go and do that. Then I will come back and praise Him with those words of praise and I will fall down prostrate before Him. He will say, ‘O Muhammad, raise your head. Speak and intercession will be granted to you, ask and you will be given, intercede and your intercession will be accepted.’ I will say, ‘O Lord, my ummah, my ummah!’ He will say, ‘Go and bring forth everyone in whose heart there is faith the weight of a small ant or a mustard-seed.’ So I will go and do that. Then I will come back and praise Him with those words of praise and I will fall down prostrate before Him. He will say, ‘O Muhammad, raise your head. Speak and intercession will be granted to you, ask and you will be given, intercede and your intercession will be accepted.’ I will say, ‘O Lord, my ummah, my ummah!’ He will say, ‘Go and bring forth from the Fire everyone in whose heart there is faith the weight of the lightest, lightest grain of mustard-seed.’ So I will go and bring them forth.”
When we left Anas I [the narrator of the hadeeth] said to some of our companions, “Why don’t we go to al-Hasan, who is hiding in the house of Abu Khaleefah, and tell him what Anas ibn Maalik has told us?” So we went to him, greeted him with salaam and he gave us permission to enter. Then we said, “O Abu Sa’eed, we have come to you from your brother Anas ibn Maalik, and we have never heard anything like what he narrated to us about intercession.” He said, “Tell me.” So we narrated the hadeeth to him and we came to this point and he said, “Keep going.” We said, “He did not tell us any more.” He said, “He told me this hadeeth when he was a young man, twenty years ago. I do not know if he forgot or if he did not want to let you depend on what he might have said. We said, “O Abu Sa’eed, tell us.” He smiled and said, “ Man was created hasty. I only mentioned that because I wanted to inform you of it. Anas told me the same as he told you, and said that the Prophet (peace and blessings of Allaah be upon him) added: “Then I will come back a fourth time and praise Him with those words of praise and I will fall down prostrate before Him. He will say, ‘O Muhammad, raise your head. Speak and intercession will be granted to you, ask and you will be given, intercede and your intercession will be accepted.’ I will say, ‘O Lord, give me permission (to bring forth) all those who said Laa ilaaha ill-Allaah.’ He will say, ‘By My Might, My Majesty, My Supremacy and My Greatness, I will most certainly bring forth from it those who said Laa ilaaha ill-Allaah.’” (Narrated by al-Bukhaari, 7510)
