Is it permissible to wear a shirt that says "No paradise," and does it invalidate the prayer if one is wearing it?

If the phrase is intended to deny the existence of Paradise, which has been prepared for the believers, then it is invalid and contains a symbol of disbelief, which is not permissible to wear. The presence of this symbol does not affect the validity of the prayer, provided that the garment is pure and covers the 'awrah.