Lyric discussion by herbivore 

Cover art for This Is The Day lyrics by Cranberries, The

It does start out by saying "I never had a friend like you," but I think it's deeper than it seems.

"These thoughts, they circle in my mind This is the day The demons I can't leave behind This is the day"

She's struggling to get rid of the demons that follow her (maybe addiction, anger, lust, and other sins). When she says "This is the day," maybe she's talking about a day of salvation. She has another song called "Salvation" and in her song "Just my Imagination" she says, "I have always kept my faith in love/ it's the greatest thing from the man above" so she's obviously spiritual.

"Don't be insecure I'll be at your door I will always be there for you"

This reminds me of what Christ said to the church in Revelation 3:20, "Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me."

Then she goes on to sing "Faith will save you" over and over again, not "They will save you." She says "stay" several times, too, possibly telling us to stay in the faith.

"Pour forth thy grace into my mind This is the day Pour forth thy grace, thou art Divine This is the day"

Here the meaning becomes a lot more obvious. She's asking for the grace of God, saying this is the day of salvation.

"But the wind might change I will still remain I will still be here But the wind might change I will still remain I will always be there for you"

God won't leave you. Stay in the faith.