Jesus
Where was Jesus during the three days before the resurrection?
Jesus tells the criminal dying beside him, "today you will be with me in paradise"—a promise suggesting his human spirit went somewhere immediately upon death, described as "paradise," while his body remained in the tomb. Luke also records his final words as entrusting his spirit directly to the Father.
Christian traditions describe this period, and "paradise" itself, in somewhat different ways. Some understand it as essentially another name for the presence of God or heaven itself. Others, particularly in Catholic and Orthodox thought, have historically distinguished it from final heavenly glory, describing something closer to a waiting place for the righteous dead prior to Christ's resurrection and ascension.
What all major traditions affirm together is that Jesus' body remained in the tomb while something continued—his human spirit, personally present with God—during those three days, and that his identity and consciousness weren't simply suspended or ended by death.
Bible quotations in these answers are generally taken from the Christian Standard Bible®, Copyright © 2017 by Holman Bible Publishers. Used by permission. Christian Standard Bible® and CSB® are federally registered trademarks of Holman Bible Publishers. Some biblical wording may be paraphrased or follow other translations.