Mark 1:15

The time, i. e. the great fore-ordained and predicted time of the Messiah.

the kingdom of God or as it is called in St Matthew the Kingdom of the Heavens(comp. Daniel 2:44; Daniel 7:13-14; Daniel 7:27), denotes here the Kingdom of grace, the visible Church, of which our Lord described (a) in the parable of "the Mustard Seed" (Matthew 13:31-32), its slight and despised beginning;(b) in that of "the Hidden Leaven" and the "Seed growing secretly," its hidden and mysterious working(Matthew 13:33; Mark 4:26-29); (c) and again in the first two Parables its final and assured triumphin spite of the obstacles set forth in the Parable of "the Tares" (Matthew 13:24-30).

believe Rather believe in, repose your faith on, the Gospel.