"A Christian is one who make it easier for other people to believe in God."

I believe that a Christian is a person who has believed in the Lord Jesus Christ for their salvation and eternal life.

Is "making it easier for other people to believe" part of the mission?  In a way, yes.  But in a big way, no.

It's my job to preach the gospel.  It's the job of the Holy Spirit to regenerate the heart and draw people to the Father.  So, in a way, the preaching of the gospel IS helping others to believe.

But I suspect what is meant by "make it easier for other people to believe" is really

"make the gospel so non-threatening to the lifestyle of sinners that it becomes meaningless to save, but people can go on believing that they're okay because nobody ever made it clear that they weren't."

There is a cost to believing, and we are to count the cost.  If we make the gospel "easy," when life isn't, faith is shallow.