Here's the simplest answer: Within weeks, the disciples proclaimed the resurrection of Jesus Christ, that He had been bodily raised from the dead and appeared to them. ↗
The first thing that stuck in the minds of the disciples was not the empty tomb, but rather the empty grave clothes - undisturbed in form and position. ↗
The wisdom of God's Word is quite clear on believers being unequally yoked. And marrying someone who is not a Christian - who is not a daily disciple of Christ - is being unequally yoked, regardless of what their beliefs might be. ↗