I will try to explain, and I will also point out why I think that Relativity is compatible with Christ.
According to Einstein, space seems to stretch as the ship accelerates so you cannot make such a measurement. It is unclear to me whether space stretches, or density increases or time lengthens, but Physicists seem to believe that space or time change preventing the conditions you have predicted. Things that seem like constants are not constants when you accelerate.
Einstein is not the enemy of truth or of churches. He believes in God. The philosophical difference between you and him is small, perhaps smaller than you imagine. According to his discovery of Relativity, time is like a painting with each person living in its time, never ceasing to exist. You live now, Abraham lives thousands of years ago, and some people live in the future. All can pray for one another, all being part of time. All are alive in their own time, never disappearing. This is the implication of Relativity. It is compatible with Christ I think, because to live is Christ and to die is gain. All are one in Christ. To follow Christ means denying ourselves, and I think this fits well with Relativity.