John 11:9-10
"Are there not twelve hours in the day?" replied Jesus. "If any one walks in the daytime, he does not stumble--because he sees the light of this world.
Romans 9:32-33
And why? Because they were pursuing a righteousness which should arise not from faith, but from what they regarded as merit. They stuck their foot against the stone which lay in their way;
1 Peter 2:8
and "a Stone for the foot to strike against, and a Rock to stumble over." Their foot strikes against it because they are disobedient to God's Message, and to this they were appointed.
1 John 2:10-11
He who loves his brother man continues in the light, and his life puts no stumbling-block in the way of others.