Broncos QB Tim Tebow is winning games because of God, pure and simple ... this according to one of Tim's Colorado pastors.

Pastor Wayne Hanson -- who runs Summit Church in Castle Rock, CO where Tim's dad often speaks -- tells TMZ God is actively intervening in Denver Broncos football games ... and aiding Tim on the field because of his strong faith.

Hanson tells us, "It's not luck. Luck isn't winning 6 games in a row. It's favor. God's favor."

Pastor Hanson adds, "God has blessed his hard work." 

We asked Hanson if Tebow would be winning games if he wasn't such a strong believer -- and the pastor replied, "No, of course not."

So far, it's the only plausible explanation for this insane Broncos winning streak.