He didn't say he would reincarnate someday into a future life. He said three days after being buried he would show himself alive to those who saw his crucifixion. On that third day, Jesus' tomb was found empty and many people testified that they saw him alive again. He now offers eternal life to us. It's a two-way relationship.
Many religions focus on a person's spiritual efforts.
Christianity is a two-way interaction between you and God. He welcomes us to go to him. You can communicate with God, who will answer your prayer, give you greater peace and joy, provide direction, show you his love, and transform your life. But it means that in the midst of life, you can relate to God who is willing to be involved in your life and faithful in his love. This is not a commitment to a method of self-improvement like the Eight Fold Path or the Five Pillars, or meditation, or good works or even the Ten Commandments.