Do I have to be a Christian?

Zoës are not the same as Christians

What counts is what the person did with their life, not what they said, not a legal/verbal transaction  that regardless of anything else sets them up with eternal Zoë life. Confessing Christ means living Christ, living Christ is, with or without words, confessing Christ. Most Zoës are Christians but it is far from automatic: Being a follower of Christ, if you let it, is directly transformative. But anyone can open themselves to the influence of the Spirit of Love, the Holy Spirit of God. There are Jewish, Muslim, Hindu, Buddhist, Pagan, and Indigenous Zoës and there are Christian Bios. It all depends on how well you loved God and loved others. Any Hindu who personally fed and clothed the poor would rank far higher in the Kingdom than a Christian who pastored a mega-church and lived a selfish lifestyle, because that pastor tossed God’s pearls into the pig pen. God honors any belief system that loves the Creator God and expresses that as selfless love for fellow human beings. Look up the “Nostra aetate” statement of Vatican II and other statements supporting “inclusivism.” See particularly John 10:16: “And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.”

According to the Gospel of Matthew 25:34-40:

Then the King will say to those on his right, ‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.’

“Then the righteous will answer him, ‘Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? When did we see you a stranger and invite you in, or needing clothes and clothe you? When did we see you sick or in prison and go to visit you?’

“The King will reply, ‘Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.’” 

Even an atheist who devoted his life to serving others would by extension have been serving God, so God does not exclude atheists. See the recent words of Pope Francis in that regard.

Bios resurrection is for everyone else

Bios resurrection does not depend on faith or actions during life except that it is not automatic: a person God deemed irredeemably evil would be left behind in death. The question remains whether there is anyone God cannot redeem.